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diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/1-Elements_of_Optics_And_Quantum_Physics_.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/1-Elements_of_Optics_And_Quantum_Physics_.ipynb
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+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 1: Elements of Optics And Quantum Physics "
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.10: Degree_of_polarisatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example no 1-10\n",
+"//page no. 26\n",
+"clc;\n",
+"clear;\n",
+"//p=m/{m+[2*n/(1-n)^2]^2};\n",
+"\n",
+"m=5;            //no. of reflective plates\n",
+"n=1.33;         //refractive indices\n",
+"p=m/{m+[2*n/(1-(n)^2)]^2}; //degree of polarisation\n",
+"printf('\n The degree of polarisation is %0.1f    \n',p);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.11: Number_of_refractive_Plates.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example no 1-11\n",
+"//page no. 26\n",
+"clc;\n",
+"clear;\n",
+"//m= p*{m+[2*n/(1-n)^2]^2};\n",
+"\n",
+"n=1.5;          //refractive indices\n",
+"p=0.45;         //degree of polarisation\n",
+"m={p*[2*n/(1-n^2)]^2}/(1-p);\n",
+"printf('\n Thus it will require %0.0f reflective plate to achive a degree of polarization equal to 0.45',m);        //Result  mis rounded of to nearest integer"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.12: Ratio_of_Optical_Ray.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"//Example no 1-12\n",
+"//page no. 27\n",
+"clc;\n",
+"clear;\n",
+"//I1/I0=cos(w)^2\n",
+"//k=I1/I0;\n",
+"\n",
+"w=30;               //angle bw polarizer and analyser in degee\n",
+"k=cosd(w)^2;\n",
+"disp(k,'The ratio of optical ray intensity ,I1/I0=');           //Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.13: Angle_between_polariser_and_analyzer.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example no 1-13\n",
+"//page no. 27\n",
+"clc;\n",
+"clear;\n",
+"//I1/I0=cos(w)^2\n",
+"//Given I1/I0=0.55\n",
+"\n",
+"k=sqrt(0.55);  //from above formulae\n",
+"printf('\n cos w is %0.2f ',k);\n",
+"printf('\n The angle bw polarizer and analyser , w is %0.0f degree',acos(k)*180/%pi);//Result\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.14: find_time_difference_and_phase_difference.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Example no 1-14\n",
+"//page no. 29\n",
+"clc;\n",
+"clear;\n",
+"disp('Solution (i) is ');\n",
+"ne=1.4;//refractive index\n",
+"no=1.25;            //refractive index\n",
+"c=3*10^8;                   //in m/s\n",
+"T=2*10^-5;  //in m\n",
+"l=740;      //in nm\n",
+"t=[ne-no]*T/c;      //time difference\n",
+"printf('\n Time difference, t is %0.2f ps',t*10^12);// result\n",
+"disp('Solution (ii) is ');\n",
+"le=l/ne; \n",
+"lo=l/no;\n",
+"fi=2*%pi*T*(1/le-1/lo)*10^9;\n",
+"printf('\n Phase difference is %0.1f rad',fi);// result\n",
+"// Answer misprinted in book\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.15: Find_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"//page no. 31\n",
+"//Example no 1-15\n",
+"//E=h*v=h*c/l;\n",
+"clc;\n",
+"clear;\n",
+"E=3;       //In KeV\n",
+"//1eV=1.6*10^-19\n",
+"h=6.63*10^-34;  //plank constant in J/s\n",
+"c=3*10^8;           // speed of light in m/s\n",
+"l=h*c/(E*10^3*1.6*10^-19);// wavelength  in nm\n",
+"printf('wavelength of a electromagnetic radiation is %0.3f nm',l*10^9);//result\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.16: Compute_the_constant_phi.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"//page no. 31\n",
+"//Example no 1-16\n",
+"clc;\n",
+"clear;\n",
+"disp('Solution (i) is ');\n",
+"l=670//in nm\n",
+"h=6.63*10^-34;  // plank constant in J/s\n",
+"c=3*10^17//speed of light in nm/sec\n",
+"Ek=0.75//In eV\n",
+"phi=(h*c/l)/(1.6*10^-19) -Ek;\n",
+"phi=round(phi*10)/10;           //round to 1 decimal point\n",
+"printf('\n Characteristic of material = %0.1f eV\n',phi);//result\n",
+"disp('Solution (ii) is ');\n",
+"fc=phi*1.6*10^-19/h*10^-12;// frequency in THz//result\n",
+"fc=round(fc);\n",
+"printf('\n Cuttoff frequency is = %0.0f THz\n',fc);//result\n",
+"lc=c/(fc*10^12);       //in nm\n",
+"printf('\n Cuttoff wavelength is = %0.0f nm\n',lc);//result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.17: Voltage_required_to_accelerate_an_electron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"//page no. 31\n",
+"//Example no 1-17\n",
+"clc;\n",
+"clear all;\n",
+"disp('Solution (i) is ');\n",
+"l=0.045;//wavelength in nm\n",
+"h=6.63*10^-34;      //planks constant in J/s\n",
+"c=3*10^8;        //speed of light in m/s\n",
+"E=h*c/l/10^-9;    //energy of photon in eV\n",
+"mprintf('\n E = %e J',E);\n",
+"E1=E/(1.6*10^-19);    // energy in joule\n",
+"mprintf('\n E = %e eV',E1);\n",
+"e=1.6*10^-19;    // charge of electron\n",
+"disp('Solution (ii) is ');\n",
+"V=E/e;\n",
+"printf('\n Required voltage is = %0.2f KV',V/1000);// result\n",
+"\n",
+"// Value of wavelenght in problem is .45 but in the solution is .045 \n",
+"//the value considered above is .045\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.18: Compute_uncertainity_in_electron_velocity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//page no. 36\n",
+"//Example no 1-18\n",
+"clc;\n",
+"clear;\n",
+"\n",
+"disp('Solution (i) is ');\n",
+"x=620// difference in particle momentum In nm\n",
+"h=6.63*10^-34// planks constant In J/s\n",
+"//p=h/(4*%pi*x);\n",
+"//m*v=h/(4*%pi*x);\n",
+"m=9.11*10^-31 //In kg // mass of electron\n",
+"v=h /(4*%pi* x *10^-9*m);// electron velocity\n",
+"printf('\n The uncertanity in electron velocity is %0.0f m/s  \n',v);// result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.1: Arrival_time_difference_between_two_monochromatic_optical_beams.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Example1-1\n",
+"//Given\n",
+"clc;\n",
+"clear all;\n",
+"printf('(i)   t1=d/c  \n');\n",
+"printf(' (ii)  t2=[(d-5)/c]+[5/v2] \n');\n",
+"printf('       v2=c/n2      \n');\n",
+"printf('       t2=(d+2.5)/c\n');\n",
+"printf(' (iii) delta_t=t2-t1=(d+2.5-d)/c\n');\n",
+"c=3*10^8;       //Speed of light in m/s\n",
+"delta_t=2.5*10^-2/c;            //converted 2.5 cm into meters\n",
+"printf('The time difference %e s',delta_t );\n",
+"printf('\n Arrival time difference of two monochromatic beams is %0.0f ps',delta_t*10^12)\n",
+"// Answer misprinted in the book"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.2: Calculate_angle_of_refraction_velocity_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//given \n",
+"//page no 5\n",
+"clc;\n",
+"clear;\n",
+"//Applying Snell's law\n",
+"a=1*sin(428)/1.333;//a=sin(w2)\n",
+"printf('Angle of refraction is %0.1f\n ',a)\n",
+"printf('\n Angle of refraction is %0.0f degree \n ',asin(a)*57.27)\n",
+"c=3*10^8;           //speed of light in m/s\n",
+"n2=1.333;           //refractive index of 2nd medium\n",
+"v2=c/n2;            //velocity in second medium in m/s\n",
+"n1=1;               //refractive index of 1st medium\n",
+"l1=620;             //in nm   wavelength\n",
+"printf('\n Velocity of optical ray through medium second %0.02f*10^8 m/s\n',v2/10^8);\n",
+"l2= (n1*l1)/n2;     //wavelength in 2nd medium in nm\n",
+"printf('\n Wavelenght of optical ray through medium second %0.1f nm',l2);       //Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.3: Angle_of_refration_and_Deviation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//given \n",
+"//page no 5 \n",
+"clc;\n",
+"clear;\n",
+"n1=1;                   //refractive index of air\n",
+"n2=1.56;                //refractive index of medium\n",
+"w1=60;      //in deg C\n",
+"//using snell's law\n",
+"a= n1*sind(w1)/n2;             //a=sin(w1)\n",
+"w2=asind(a);                   //in degree\n",
+"printf('Angle of refraction is %0.2f degree\n ',w2);\n",
+"B=w1-w2;                         //in degree\n",
+"printf('Angle of deviation is %0.1f degree\n ',B)\n",
+"// The answer doesn't match because of priting errorsin calculation as sin(608)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.4: Find_optical_Path_and_angle_phi.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//given \n",
+"//page no 6\n",
+"clc;\n",
+"disp('Solution (i)');\n",
+" w=5/12.5; //          tan(w)=5/12.5;\n",
+"printf('\n The value of tan(w2) is %0.1f \n',w);\n",
+"w2=atan(w)*180/%pi;\n",
+"//w2=atan(w)*180/%pi\n",
+"printf('\n The value of w2 is %0.1f degree\n',w2);\n",
+"printf('\n The value of sin(w2) is %0.2f \n',sin(w2*%pi/180));\n",
+"disp('Solution (ii)');\n",
+"//Applying snell's law\n",
+"n1=1.05;\n",
+"n2=1.5;\n",
+"w1=(n2*sin(w2*%pi/180))/n1;//a=sin(w1)\n",
+"printf('\n The value of sin(w1) is %0.2f \n',w1);\n",
+"printf('\n The value of w1 is  %0.0f degree \n',asin(w1)*180/%pi);\n",
+"//value of w1\n",
+"//tan(w1)=(p-x)12.5;\n",
+"k=0.62*12.5;\n",
+"d=1.05*[(12.5)^2+(k)^2]^0.5 +1.5*(12.5^2+5^2)^0.5;//d=1.05[(h1)^2+(k)^2]^0.5 +n2(h2^2+x^2)^0.5;\n",
+"printf('\n the optical distance is %0.2f cm\n',d);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.5: Find_Phase_velocity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Ex1_5\n",
+"//given \n",
+"//page no 11\n",
+"clc;\n",
+"clear;\n",
+"c=3*10^8;\n",
+"disp('Solution (i) is ');\n",
+"ri=1.5;//refractive index\n",
+"u=830// in nm\n",
+"l=u/ri;      //in nm\n",
+"printf('\n Wavelength is %0.0f nm \n',l);\n",
+"disp('Solution (ii) is ');\n",
+"l=round(l);                 // rounding to nearest integer\n",
+"f=c/(l*10^-9)*10^-12;       //in THz\n",
+"printf('\n  frequency is %0.0f THz\n',f);\n",
+"disp('Solution (iii) is ');\n",
+"f=round(f);                 // rounding to nearest integer\n",
+"v=l*10^-9*f*10^12;          //in m/s\n",
+"mprintf('\n  phase velocity  is %.3e m/s\n',v);//answer is getting rounding off due to larger calculation\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.6: find_wavelength.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Ex1_6\n",
+"//given \n",
+"//page no 12\n",
+"clc;\n",
+"clear;\n",
+"disp('Solution (i) is ');\n",
+"l=720;      //wavelength in nm\n",
+"n=1.5;          //refractive index\n",
+"lm=l/n;\n",
+"disp('nm',lm,'Wavelenth is');       //result\n",
+"disp('Solution (ii) is ');\n",
+"c=3*10^8;           //in m/s speed of light\n",
+"u=c/n;\n",
+"disp('m/s',u,'Velocity  is');       //result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.7: Find_wavelength_of_Light.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Ex1_7\n",
+"//given \n",
+"//page no 12\n",
+"clc;\n",
+"clear;\n",
+"disp('Solution (i)');\n",
+"c=3*10^8;       //in m/s speed of light\n",
+"l=640;          //in nm\n",
+"u=2.2*10^8;     //in m/s\n",
+"lm=u*l/c;           //wavelenth in medium\n",
+"printf('\n The wavelength is %0.1f nm\n',lm);// The answer in the book is misprinted \n",
+"disp('Solution (ii)');\n",
+"n=l/lm;         //refractive index\n",
+"printf('\n Refractive Index is %0.3f \n',n);//The answer in the book is misprinted"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.8: Ratio_of_input_output_intensity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Ex1_8\n",
+"//given \n",
+"//page no 12\n",
+"clc;\n",
+"clear;\n",
+"//k=aa+as=6.3;\n",
+"//Given values from research\n",
+"k=6.3;      //combined attenuation due to absorption and scattering\n",
+"d=25;       //in cm\n",
+"disp('Solution (ii)');\n",
+"//Io/Ii=exp(-(ao+ai)*d);  d in m\n",
+"j=exp(-(k)*d/100);  //Io/Ii ratio\n",
+"printf('\n  Io is %0.3f of Ii \n',j);       //result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.9: Compute_length_of_Tube.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Ex1_9\n",
+"//given \n",
+"//page no 13\n",
+"clc;\n",
+"clear;\n",
+"//      Given formula   Io/Ii=exp(-(ao+ai)*d);\n",
+"//       k=aa+as=63.1;\n",
+"//       Io/Ii=1.5\n",
+"d=log(.15)/-63.1;       //length of tube\n",
+"printf('\nLength of tube, d = %0.0f cm   \n',d*100);      //Result"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/10-Optical_Modulation.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/10-Optical_Modulation.ipynb
new file mode 100644
index 0000000..f82791e
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/10-Optical_Modulation.ipynb
@@ -0,0 +1,103 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 10: Optical Modulation"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.1: Required_Biasing_voltage.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 10\n",
+"//page no 354\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Vpi=1;         //Assumed 1 because we can not use a variable on RHS \n",
+"//Vpi is Violtage swing\n",
+"A=0.25;         //chirping\n",
+"//V1=(AV1p+Vp)/2\n",
+"V1=(A*Vpi+Vpi)/2;\n",
+"printf('\n V1= %0.3f Vpi',V1) \n",
+"V2=V1-Vpi;\n",
+"printf('\n V2= %0.3f Vpi',V2) "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 10.2: Biasing_range.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 10\n",
+"//page no 354\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Vpi=1;         //Assumed 1 because we can not use a variable on RHS\n",
+"//Vpi is Violtage swing\n",
+"disp('for alpha=0.3');\n",
+"A=0.3;         //chirping\n",
+"//V1=(AV1p+Vp)/2\n",
+"V1=(A*Vpi+Vpi)/2;\n",
+"printf('\n V1= %0.2f Vpi',V1) \n",
+"V2=V1-Vpie;\n",
+"printf('\n V2= %0.2f Vpi\n',V2) \n",
+"disp('for alpha=0.8');\n",
+"A=0.8;         //chirping\n",
+"//V1=(AV1p+Vp)/2\n",
+"V1x=(A*Vpi+Vpi)/2;\n",
+"printf('\n V1= %0.1f Vpi',V1x) \n",
+"V2x=V1x-Vpi;\n",
+"printf('\n V2= %0.1f Vpi',V2x) \n",
+"printf('\n Biasing range is %0.2f Vpi <= V1 <= %0.2f Vpi',V1,V1x) \n",
+"printf('\n Biasing range is %0.1f Vpi <= V2 <= %0.2f Vpi',V2x,V2) "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/11-Multiplexing.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/11-Multiplexing.ipynb
new file mode 100644
index 0000000..5ae93f4
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/11-Multiplexing.ipynb
@@ -0,0 +1,128 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 11: Multiplexing"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.1: Cross_talk_in_refrence_to_the_number_of_channel.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 11\n",
+"//page no 386\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"q=4.9*10^-18;           //in m/W.GHz raman  gain slope\n",
+"f=100;                  //in GHz\n",
+"A=50*10^-6;             //cross sectional area in micro  meter square\n",
+"P0=3.5;           //in mW\n",
+"Le=10*10^3;\n",
+"G=q*f*10^6/2/A;\n",
+"N=20;\n",
+"mprintf('\n G = %e ',G);\n",
+"CT=N*(N-1)*(P0*10^-3*G*Le)/2;\n",
+"printf('\n CT(L) = %0.2f ',CT);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.2: Capacitor_value_of_PLL_section.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 11\n",
+"//page no 410\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"K0=2*%pi*625;           //in MHz/V\n",
+"Ip=0.6;             //in mA\n",
+"N=64;           \n",
+"w=2.44;             //in Mhz\n",
+"Z=5;\n",
+"Vout=5;         //in V\n",
+"C=(4*K0*10^6*Ip*10^-3*Z)/(2*%pi*N*w*w*10^12);\n",
+"printf('\n The value of capacitance is %0.0f nF',C*10^9)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 11.3: Value_of_damping_coefficient.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 11\n",
+"//page no 410\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"K0=2*%pi*625;           //in MHz/V\n",
+"Ip=0.35;             //in mA\n",
+"N=64;           \n",
+"w=2.44;         //in MHz\n",
+"Z=5;\n",
+"Vout=4;         //in V\n",
+"C=22;           //in nF\n",
+"Z=sqrt((2*%pi*N*w^2*C)/(4*Ip*K0*0.25))\n",
+"printf('\n Zeta is = %0.0f' ,Z)\n",
+""
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/12-Optical_Systems_.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/12-Optical_Systems_.ipynb
new file mode 100644
index 0000000..9efbcbb
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/12-Optical_Systems_.ipynb
@@ -0,0 +1,1754 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 12: Optical Systems "
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.10: Calculate_chromatic_dispersio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 444\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=200;     //in km\n",
+"dL=1550;            //in nm\n",
+"R=10;           //in Gb/s\n",
+"Cd=17;          //in ps/nm-km\n",
+"w=0.1;          //Assused bandwidth\n",
+"Cd200=Cd*L;\n",
+"printf('\n Dispersion by 200km ofc = %0.1f*10^3 ps/nm',Cd200/10^3);\n",
+"TCd=w*Cd200;\n",
+"printf('\n total chromatic  dispersion = %0.2f*10^3 ps',TCd/10^3);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.11: Calculate_dispersion_penalty.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 480\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=1.5;          //in km\n",
+"Ls=L/3;         //in km\n",
+"BwF=600;                //in MHz\n",
+"fb=1;               //in Gbps\n",
+"Bdlaser=0.71*BwF*L^-0.7*Ls^-0.25;\n",
+"printf('Laser bandwidth is %0.0f MHz',Bdlaser);     //Answer in book is approx\n",
+"mD=0.85*(fb*10^3/Bdlaser)^2;\n",
+"printf('\n Mean dispersion penalty is %0.1f dB',mD);     //Answer in book is approx"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.12: Calculate_maximum_length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 481\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"E=0.182;            //from table 12-11 for 2dB dispersion penalty\n",
+"fb=622;         //in Mb/s\n",
+"dl=4;           //in nm\n",
+"ofdisp=3;       //in ps/km-nm\n",
+"Dmax=E/(10^-6*fb*dl);\n",
+"printf('\n Dmax is %0.1f ps/nm',Dmax);   \n",
+"Lmax=Dmax/ofdisp;\n",
+"printf('\n Maximum link distance is %0.1f km',Lmax); \n",
+"//Answer in the book is rounded"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.13: Calculate_the_maximum_length_of_optical_link.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 481\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"E=0.115;            //from table 12-11 for 2dB dispersion penalty\n",
+"fb=622;         //in Mb/s\n",
+"dl=4;           //in nm\n",
+"ofdisp=3;       //in ps/km-nm\n",
+"Dmax=E/(10^-6*fb*dl);\n",
+"printf('\n Dmax is %0.1f ps/nm',Dmax);   \n",
+"Lmax=Dmax/ofdisp;\n",
+"printf('\n Maximum link distance is %0.1f km',Lmax);   \n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.14: Calculate_maximum_dispersion_mean_link_margin_sigma_link_margin.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 481\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"mc=0.4;         //in dB\n",
+"sc=0.0;         //in dB\n",
+"dmax=2.8;       //in dB\n",
+"mt=-4.9;       //in dBm\n",
+"st=0.5;       //in dBm\n",
+"mr=-38.1;       //in dBm\n",
+"sr=0.48;         //in dBm\n",
+"mco=0.35;       //in dB\n",
+"sco=0.20;       //in dB\n",
+"ms=0.2;       //in dB\n",
+"ss=0.1;       //in dB\n",
+"E=0.182;            //from table 12-11 for 2dB dispersion penalty\n",
+"fb=156;         //in Mb/s\n",
+"dl=4;           //in nm\n",
+"ofdisp=2.8;         //in ps/nm-km\n",
+"Nco=7;\n",
+"mD=2;\n",
+"sD=0.1;\n",
+"sH=2;\n",
+"sCR=0.25;\n",
+"Ns=4;\n",
+"mH=0;\n",
+"mCR=0.5;\n",
+"L=50;\n",
+"Ls=10;\n",
+"Dmax=E/(10^-6*fb*dl);\n",
+"printf('\n Dmax is %0.0f ps/nm\n',Dmax);   \n",
+"Lmax=Dmax/ofdisp;\n",
+"printf('\n Maximum link distance is %0.0f km\n',Lmax);   \n",
+"mM=mt-mr-(mc*L+mco*Nco+ms*Ns+mD+mH+mCR);\n",
+"printf('\n Mean link margin is %0.2f dB\n',mM);   \n",
+"sM=sqrt(st^2+sr^2+sc^2*L*Ls+sco^2*Nco+sD^2*sH^2+sCR^2);\n",
+"printf('\n Sigma link margin is %0.3f dB\n',sM);   \n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.15: Compute_maximum_dispersion_and_nominal_distribution.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 483\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"E=0.115;            \n",
+"fb=622;         //in Mb/s\n",
+"dl=4;           //in nm\n",
+"mt=0.1;       //in dBm\n",
+"mr=-31.5;         //in dBm\n",
+"mc=0.41;         //in dB\n",
+"L=25;\n",
+"mco=0.12;       //in dB\n",
+"Nco=2;\n",
+"ms=0.15;       //in dB\n",
+"Ns=4;\n",
+"mD=1;\n",
+"mH=0;\n",
+"mCR=0;\n",
+"\n",
+"sc=0.0;         //in dB\n",
+"st=-0.15;       //in dBm\n",
+"sr=0.3;       //in dBm\n",
+"sco=0.08;       //in dB\n",
+"ss=0.1;       //in dB\n",
+"ofdisp=2.8;         //in ps/nm-km\n",
+"sD=2;\n",
+"sH=0;\n",
+"sCR=0.0;\n",
+"Ls=12;\n",
+"\n",
+"Dmax=E/(10^-6*fb*dl);\n",
+"printf('\n Dmax is %0.2f ps/nm\n',Dmax);   \n",
+"Lmax=Dmax/ofdisp;\n",
+"printf('\n Maximum link distance is %0.1f km\n',Lmax);   //in book 4 is misprint for solving \n",
+"mM=mt-mr-(mc*L+mco*Nco+ms*Ns+mD+mH+mCR);\n",
+"printf('\n Mean link margin is %0.1f dB\n',mM);         //wrong in book\n",
+"L=60;\n",
+"Ls=12;  \n",
+"sM=sqrt(st^2+sr^2+sc^2*L*Ls+sco^2*Nco+ss^2*Ns+sD^2*sH^2+sCR^2);\n",
+"printf('\n Sigma link margin is %0.2f dB\n',sM);   \n",
+"spm=mM-2*sM-1;\n",
+"printf('\n System power margin is %0.2f dB\n',spm);   //answer is slighty difeerent due to mM=19.5\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.16: Calculate_maximum_dispersion_and_maximum_distance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 484\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"E=0.115;            \n",
+"fb=1062;         //in Mb/s\n",
+"dl=6;           //in nm\n",
+"mt=-8;       //in dBm\n",
+"mr=28.7;         //in dBm\n",
+"mc=0.4;         //in dB\n",
+"L=5;\n",
+"mco=0.12;       //in dB\n",
+"Nco=8;\n",
+"ms=0.2;       //in dB\n",
+"Ns=4;\n",
+"mD=1;\n",
+"mH=0;\n",
+"mCR=1;\n",
+"\n",
+"sc=0.0;         //in dB\n",
+"st=0.6;       //in dBm\n",
+"sr=0.75;       //in dBm\n",
+"sco=0.08;       //in dB\n",
+"ss=0.1;       //in dB\n",
+"ofdisp=2.8;         //in ps/nm-km\n",
+"sD=2;\n",
+"sH=0;\n",
+"sCR=0.25;\n",
+"Ls=12;\n",
+"\n",
+"Dmax=round(E/(10^-6*fb*dl));        //taking to nearest integer in ps/nm\n",
+"printf('\n Dmax is %0.0f ps/nm\n',Dmax);   \n",
+"Lmax=Dmax/ofdisp;\n",
+"printf('\n Maximum link distance is %0.2f km\n',Lmax);   \n",
+"mM=mt+mr-(mc*L+mco*Nco+ms*Ns+mD+mH+mCR);\n",
+"printf('\n Mean link margin is %0.1f dB\n',mM);\n",
+"L=60;\n",
+"Ls=12;  \n",
+"sM=sqrt(st^2+sr^2+sc^2*L*Ls+sco^2*Nco+ss^2*Ns+sD^2*sH^2+sCR^2);\n",
+"printf('\n Sigma link margin is %0.2f dB\n',sM);   \n",
+"mM=round(mM*10)/10;     //talking only to 1 decimal place and rounding of other values\n",
+"spm=mM-2*sM-1;\n",
+"printf('\n mM-2*sM = %0.2f\n',mM-2*sM);\n",
+"printf('\n System power margin is %0.2f dB\n',spm);  //answer is slighty diferent due to m\sM=1.03\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.17: Calculate_the_CSO_distortio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 486\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Ncso=50;\n",
+"a=3.6*10^-3;\n",
+"m=0.05;\n",
+"CSO=10*log10(Ncso*(a*m)^2);\n",
+"printf('\n CSO distortion for 50 channel optical system = %0.1f dB\n',CSO);   "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.18: Calculate_the_required_AM_modulatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 486\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"CSO=-59.8;  //in dB\n",
+"y=10^(CSO/10);\n",
+"mprintf('AM modulation depth (m) = %e\n',y);\n",
+"asq=3.6*10^-3;\n",
+"Ncso=50;\n",
+"msq=(y/Ncso/asq/asq);\n",
+"mprintf('\n m^2  = %e\n',msq);\n",
+"printf('\n Decrease of AM modulation depth decrease the CSO distortion by  = %0.0f percent',sqrt(msq)*100);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.19: Compute_the_CTO_distortio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 486\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Ncto=50;\n",
+"b=1.07*10^-2;\n",
+"m=0.05;\n",
+"CTO=10*log10(Ncto*(1.5*b*m)^2);\n",
+"printf('\n CTO distortion for 50 channel optical system = %0.1f dB\n',CTO);   \n",
+"//Answer in the book is misprinted\n",
+"//The solution in the book is calculated without multipication of Ncto"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.1: Compute_power_margi.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 431\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Pt=10;            //in microW\n",
+"Pr=1;            //in microW\n",
+"PtdBm=10*log10(Pt*10^-6/10^-3)                    //in dBm\n",
+"printf('\n Transmitter Power = %0.0f dBm',PtdBm);\n",
+"PrdBm=10*log10(Pr*10^-6/10^-3)                    //in dBm\n",
+"printf('\n Receiver Power = %0.0f dBm',PrdBm);\n",
+"Pm=PtdBm-PrdBm;\n",
+"printf('\n Power margin= %0.0f dBm',Pm);    //misprint in book"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.20: Calculate_the_CSO_and_CTO.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 487\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Ncso=80;\n",
+"a=2.43*10^-3;\n",
+"b=4.65*10^-3;\n",
+"m=0.05;\n",
+"//Part (i)\n",
+"CSO=10*log10(Ncso*(a*m)^2);\n",
+"printf('\n CSO distortion for 50 channel optical system for m = 5 percent \n CSOdB = %0.1f dB\n',CSO);   \n",
+"//Part (ii)\n",
+"CTO=10*log10(Ncso*(1.5*b*m)^2);\n",
+"printf('\n CTO distortion for 50 channel optical system for m = 5 percent \n CTOdB = %0.1f dB\n',CTO);\n",
+"//Part (iii)\n",
+"m=0.03;\n",
+"\n",
+"CSO=10*log10(Ncso*(a*m)^2);  \n",
+"// Value of a in the book is considered 2.4 instead of 2.43\n",
+"printf('\n CSO distortion for 50 channel optical system for m = 3 percent \n CSOdB = %0.1f dB\n',CSO);   \n",
+"\n",
+"//Part (iv)\n",
+"CTO=10*log10(Ncso*(1.5*b*m)^2);\n",
+"printf('\n CTO distortion for 50 channel optical system for m = 3 percent \n CTOdB = %0.1f dB\n',CTO);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.21: Calculate_the_CNR.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 487\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"RIN=-150;           //in dB\n",
+"B=4*10^6;\n",
+"m=0.04;\n",
+"CNR=10*log10(m^2/(2*10^-15*B));\n",
+"printf('\n CNR = %0.0f dB',CNR);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.22: Calculate_the_RIN.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 12\n",
+"//page no 488\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"CNR=50;           //in dB\n",
+"Bch=4*10^6;\n",
+"m=0.03;\n",
+"RIN=m^2/2/Bch/10^(CNR/10)\n",
+"mprintf('\n RIN = %e ',RIN);\n",
+"//Miscalculated answer in the book\n",
+"RINdB=10*log10(RIN);\n",
+"printf('\nRIN in Db is %.2f',RINdB)\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.23: Calculate_the_required_optical_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 490\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Ipd=0.15;           //in mA\n",
+"n=0.75;\n",
+"e=1.6*10^-19;           //electron charge\n",
+"hv=1.55*10^-19;\n",
+"Pin=hv*Ipd/n/e;\n",
+"printf('\n Pin = %0.6f mW',Pin);        //Result\n",
+"//answer in book is misprint"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.24: Calculate_the_percentage_of_optical_power_reflected_back.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 492\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"OBR=-40;            //in dB\n",
+"//y=Pref/Pin\n",
+"y=10^(OBR/10);\n",
+"printf('\n Prefl = %0.2f percent Pin',y*100);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.25: Calculate_the_output_voltage_of_an_optical_receiver.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 493\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"R=800;              //in V/W\n",
+"Pin=1.5;            //in mW\n",
+"m=0.04;\n",
+"Voutp=R*Pin*m;\n",
+"printf('\n Vout(peak) = %0.0f mV',Voutp);\n",
+"Vavg=Voutp/sqrt(2);\n",
+"printf('\n Vavg = %0.1f mV',Vavg);\n",
+"//in dB\n",
+"Vavgd=20*log10(Vavg*10^-3);\n",
+"printf('\n Vavg(in dBmV) = %0.1f ',Vavgd);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.26: Determine_the_optical_receiver_responsivity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 494\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Voutp=20;           //in dB\n",
+"Pin=1.2;            //in mW\n",
+"m=0.035;\n",
+"Vavg=10^(Voutp/20);           //in \n",
+"R=Vavg*sqrt(2)/Pin/m;\n",
+"printf('\n R = %0.1f V/W',R);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.27: Calculate_the_modulation_depth.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 494\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Voutp=28;           //in dB\n",
+"Pin=1;            //in mW\n",
+"R=800;          //in V/W\n",
+"Vavg=10^(Voutp/20);           //in \n",
+"m=Vavg*sqrt(2)/Pin/R;\n",
+"printf('\n The modulation depth ,m = %0.1f percent',m*100);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.28: Calculate_the_CNR.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 495\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Ipd=1.2;            //in mA\n",
+"m=0.04;        \n",
+"RINd=-160;               //in dB/Hz\n",
+"e=1.6*10^-19;          \n",
+"nth=8;          //in pA/Hz\n",
+"BW=4;           //in MHz\n",
+"Rin=10^(RINd/10);           //in \n",
+"\n",
+"CNR=[0.5*(m*Ipd*10^-3)^2]/[(2*e*Ipd*10^-3)+(Rin*Ipd*10^-3)^2+((nth*10^-12)^2)*BW/10^6];\n",
+"printf('Value of CNR=%e',CNR)\n",
+"CNRdB=10*log10(CNR)\n",
+"printf('\nValue of CNR in dB=%.2f dB',CNRdB)\n",
+"//Answer in the book is misprinted or wrong calculation performed in the book"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.29: Total_fiber_span_attenuation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 509\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L1=40;          //in km\n",
+"L2=100;         //in km\n",
+"A=0.2;      //in dB/Km\n",
+"TFA1=A*L1;\n",
+"\n",
+"printf('\n Total fibre span attenuation %0.0f dB\n',TFA1);\n",
+"TFA2=A*L2;\n",
+"printf('\n Total fibre span attenuation %0.0f dB\n',TFA2);\n",
+"nsd=TFA2-TFA1;\n",
+"printf('\n Noise spectral density = %0.0f dB ',nsd);\n",
+"nsd_abs=10^(nsd/10)\n",
+"printf('\n\n Absolute value of noise spectral density = %0.0f dB ',nsd_abs);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.2: Compute_power_margi.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 431\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Pt=25;            //in microW\n",
+"Prd=15;            //in dBm\n",
+"Ptd=10*log10(Pt*10^-6/10^-3)                    //in dBm\n",
+"printf('\n Transmitter Power = %0.0f dBm',Ptd);\n",
+"Pm=Ptd-Prd;\n",
+"printf('\n Power margin= %0.0f dBm',Pm);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.30: Calculate_the_SNR.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 12\n",
+"//page no 510\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"P1=2.75;            //in mW\n",
+"NFd=5;           //in dB\n",
+"bw=5;           //in GHz\n",
+"G=10;         //in dB\n",
+"hv=1.6*10^-19; //photon energy in J\n",
+"N=1;        //no of amplifiers\n",
+"NF=10^(NFd/10);     //amplifier noise figure\n",
+"SNR=10*log10(P1*10^-3/[G*hv*bw*10^9*N*NF]);     //signal to nois eratio\n",
+"printf('\n Spectral Noise density = %0.0f dB ',SNR);//result\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.31: Calculate_the_optical_power_in_fiber.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 510\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"SNRdB=40;            //in dB\n",
+"NFd=6;           //in dB\n",
+"bw=4;           //in GHz\n",
+"Gd=8;         //in dB\n",
+"hv=1.6*10^-19; //photon energy in J\n",
+"N=8; //no of amplifiers\n",
+"SNR=10^(SNRdB/10);\n",
+"NF=10^(NFd/10);     //amplifier noise figure\n",
+"G=10^(Gd/10);           //amplifer gain\n",
+"P1=10*(SNR/10)*[G*hv*bw*10^9*N*NF]/10^-3;        //optical power launched into fibre\n",
+"printf('\n Optical power required , Pl = %0.1f mW ',P1);    //Result\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.32: Compute_the_transmission_length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 12\n",
+"//page no 518\n",
+"//given\n",
+"clc;\n",
+"clear all ;\n",
+"l=1550;     //wavelength in nm\n",
+"fb=10;      //system bit rate Gb/s\n",
+"Df=17;      //fiber dispersion in ps/nm-km\n",
+"L=10^5/Df/fb^2;     //fiber length in km \n",
+"printf('\n Transmission length is %0.1f km',L);\n",
+"fb2=2.5;      //system bit rate Gb/s\n",
+"disp('for fb=2.5 Gb/s')\n",
+"L2=10^5/Df/fb2^2;       //fiber length in km \n",
+"printf(' Transmission length is %0.0f km',L2);//result misprint in book"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.33: Compute_the_maximum_bit_rate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 518\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"lembda=1550;     //wavelength in nm\n",
+"Df=17;      //fiber dispersion in ps/nm-km\n",
+"L=80     //fiber length in km \n",
+"fb=sqrt(10^5/Df/L)\n",
+"printf('\n Maximum bit rate fb = %.1f Mb/s',fb);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.34: Compute_the_solition_characteristic_length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 530\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"D=0.2;                      //dispersion constant in ps/nm/km\n",
+"Tfwhm=18;                     //ps\n",
+"Zs=0.25*Tfwhm^2/D;         // Characteristic length\n",
+"printf('\n Zs = %0.0f km',Zs);      //answer in book is miscalculated\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.35: Determine_maximum_dispersion.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 530\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"lembda=1550;         //wavelength in nm\n",
+"c=3*10^5;           //speed of light in km/s\n",
+"Zs=600;                      //in km\n",
+"Tfwhm=20;                     //in ps\n",
+"D=1/1.763^2*[2*%pi*c*Tfwhm^2/(lembda^2*Zs)];  //dispersion constant\n",
+"printf('\n dispersion constant, D = %0.2f ps/nm/km',D);      //result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.36: Calculate_the_solition_pulse_width.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 12\n",
+"//page no 530\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"l=1557;         //wavelength in nm\n",
+"c=3*10^5;           //speed of light in km/s\n",
+"Zs=550;                      //in km\n",
+"D=0.25;                     //in ps/nm/km\n",
+"Tfwhm=sqrt(1.763^2*l^2*D*Zs/(2*%pi*c));//Soliton pulse width \n",
+"printf('\n Tfwhm = %0.0f ps',Tfwhm);      //Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.37: Calculate_the_solition_peak_pulse.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 531\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"Aeff=55;            //in sq micrometer\n",
+"l=1557;         //wavelength in nm\n",
+"c=3*10^5;           //speed of light in km/s\n",
+"n2=2.6*10^-16;          //in cm^2/W\n",
+"D=0.20;                     //Dispersion constant in ps/nm/km\n",
+"Tfwhm=30;              //in ps\n",
+"Zs=[2*%pi*c*Tfwhm^2/l^2/D]/(1.763)^2 ;//charecteristic length \n",
+"printf('\n Zs = %0.0f km',Zs);       //result \n",
+"Ps=(Aeff*10^-12*l*10^-9)/(2*%pi*n2*10^-4*Zs*10^3);//Peak pulse power\n",
+"//Miscalculation in the book\n",
+"printf('\n Ps = %0.2f mW',Ps*1000);      //Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.38: Compute_the_standard_deviation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"//Chapter 12\n",
+"//page no 533\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Z=10;               //in mm\n",
+"Tfwhm=22;           //in ps\n",
+"D=0.5;              //ps/nm/km\n",
+"Aeff=55;            //in microm^2\n",
+"A=0.05;             //in km^-1\n",
+"nsp=1.5;        //spontaneous emission \n",
+"F=2;            //amplifier noise\n",
+"s=3.6*10^3*nsp*F*A*D*Z^3/(Aeff*Tfwhm);\n",
+"printf('\n sigma = %0.0f ps',s);      //Result\n",
+"\n",
+"//answer in book is misprint"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.39: Calculate_the_system_BER.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 533\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"Q1=4;           //quality factor\n",
+"Q2=6;           //quality factor\n",
+"BER1=[2*%pi*(Q1^2+2)]^-0.5*exp(-Q1*Q1/2); \n",
+"BER2=[2*%pi*(Q2^2+2)]^-0.5*exp(-Q2*Q2/2);\n",
+"printf('\n For Q=4 ,BER  = %0.0f*10^-5 ',BER1*10^5);      //Result\n",
+"printf('\n For Q=6 ,BER  = %0.1f*10^-10 ',BER2*10^10);      //Result\n",
+"//Answer second is misprinted in the book\n",
+"\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.3: Calculate_level_of_additional_power_launched.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 432\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Pt1=-18;            //in dBm for 50/125 micron fiber\n",
+"Pt2=-10;            //in dBm for 100/125 micron fiber\n",
+"Pd=Pt1-Pt2;\n",
+"printf('\n Additional  Power = %0.0f dBm',Pd);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.40: Compute_the_standard_deviation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 534\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"D=0.5;              //Dispersion constant ps/nm/km\n",
+"Ts=22;              //Pulse width in ps\n",
+"fb=10;              //system transmission rate in Gb/s\n",
+"Z1=1;                //System total length Mm\n",
+"Z2=10;                //System total length Mm\n",
+"sa1=8.6*D*D*Z1*Z1*sqrt(fb-0.99)/22/2;       //standard deviation based on accoustic effect\n",
+"sa2=8.6*D*D*Z2*Z2*sqrt(fb-0.99)/22/2;       //standard deviation based on accoustic effect\n",
+"printf('\n For Z=1000km ,sigma acoustic  = %0.2f ps ',sa1);      //Result\n",
+"printf('\n For Z=10000km ,sigma acoustic  = %0.0f ps ',sa2);      //Result\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.41: Calculate_the_collision_length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 535\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"D=0.45;              //dispersion coefficient in ps/nm/km\n",
+"Ts=22;              //Pulse width in ps\n",
+"l=0.5;         //length in nm\n",
+"Lcollision=2*Ts/l/D;        //collision length  in km\n",
+"printf('\n Lcollision  = %0.1f km ',Lcollision);      //Result\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.42: Calculate_the_half_channel_length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 537\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"f=70;           //Maximum frequencyshift in Ghz\n",
+"Ts=22;          //Pulse width in ps\n",
+"CS=1.783*f*10^9*Ts*10^-12;      //half channel seperation \n",
+"printf('\n The half channel seperation %0.2f ',CS);\n",
+"df=0.105/f/10^9/Ts/Ts/10^-24;       //maximum frequency shift\n",
+"printf('\n The maximum frequency shift %0.0f GHz',df/10^9);\n",
+"dt=0.1786/f/10^9/f/10^9/Ts/10^-12;  //time displacement\n",
+"printf('\n The time displacement %0.2f ps',dt*10^12);\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.43: Calculate_the_minimum_number_of_soliton.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 538\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"M=1;            \n",
+"N=1;            //no of collision \n",
+"S1=4;           //soliton colllision \n",
+"S2=5;       //soliton colllision \n",
+"Nc=S1*S1/4*[M*S1/2-M+N];        //minimum no of collision\n",
+"printf('\n Ncollision for S=4,is %0.0f',Nc);\n",
+"Nc2=(S2*S2-1)/4*[M*S2/2-M+N];        //minimum no of collision\n",
+"printf('\n Ncollision for S=5,is %0.0f',Nc2);\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.44: Compute_the_maximum_number_of_soliton.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 539\n",
+"//given\n",
+"clc;\n",
+"clear;\n",
+"S=4;\n",
+"n=5;\n",
+"printf('\n Maximum number of solition Collisions\n');\n",
+"for M = 1:n\n",
+"N=M;\n",
+"Nc=S*[M*S*S/3+S*(N/2-M)-N/2+2*M/3];      //minimum no of collision\n",
+"printf('\n M=%0.0f    N=%0.0f     S=%0.0f ,is     %0.0f',M,N,S,Nc);//result\n",
+"\n",
+"    \n",
+"end"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.45: Compute_the_number_of_collision.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 539\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"M=1;         //number of solition Collisions\n",
+"N=1;        // number of solition Collisions\n",
+"x=2;         \n",
+"y=1/2;\n",
+"p=3;\n",
+"p2=4;\n",
+"Tb=100;         //ps\n",
+"l=1;            //difference in wavelength in nm \n",
+"D=7*10^-2;      //ps/nm^2*km\n",
+"Zr=y*y*(Tb/l/l/D);      //regeration spacing in km\n",
+"printf('\n Zr = %0.0f km\n',Zr);\n",
+"P=(p-1)*N+(p-2)*(p-1)*M/2;\n",
+"printf('\n P(%0.0f) =%0.0f',p,P);      //result number of  Collisions\n",
+"P2=(p2-1)*N+(p2-2)*(p2-1)*M/2;      \n",
+"printf('\n P(%0.0f) =%0.0f',p2,P2);     //result number of  Collisions"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.46: Calculate_the_channel_spacing.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 12\n",
+"//page no 540\n",
+"//exa 12_46\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"Tb=100;         //bit period in ps\n",
+"dZ=0.4;         //in ps/nm/km\n",
+"Zr=150;         //Modulator spacing in km\n",
+"Ta=Tb/(dZ*Zr);      //channel spacing in nm\n",
+"printf('\n Channel spacing %0.1f nm',Ta);   //result\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.47: Compute_the_bit_period.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 12\n",
+"//page no 540\n",
+"//exa 12_47\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"Zr=200;            //Modulator spacing in km\n",
+"D=0.6;              //in ps/nm/km\n",
+"l=2;             //in nm\n",
+"Tb=l*(Zr*D);        //bit period in ps\n",
+"printf('\n Bit period Tb = %0.0f ps',Tb);//result\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.48: Calculate_the_maximum_modulator_spacing.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 12\n",
+"//page no 540\n",
+"//exa 12_48\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"D=0.5;          //ps/nm-km\n",
+"Tb=80;          //bit period in ps\n",
+"l=1.5;      //in nm\n",
+"Zr=Tb/(D*l);         //Modulator spacing in km\n",
+"printf('\n Maximum modulator spacing Zr = %0.2f km',Zr);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.49: Calculate_the_length_of_dispersion.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 12\n",
+"//page no 541\n",
+"//exa 12_49\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"Zd=100;        //in km\n",
+"Do=0.07;       //in ps/nm^2\n",
+"D1=-0.3;       //in ps/nm^2\n",
+"Ldsf=(Zd*Do)/(Do-D1);       //length of dispersion compensation fiber in km\n",
+"printf('\n Length of Dispersion compensation fiber, Ldsf = %0.0f km',Ldsf);//Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.4: Compute_link_power_budget.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 432\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Plb=10;            //in dBm for 50/125 micron fiber\n",
+"Ps=3;            //in dBm for safety margin\n",
+"Prs=-30;            //in dBm for receiver sensivity\n",
+"Pt=Plb+Ps+Prs;\n",
+"printf('\n Link power budget = %0.0f dBm',Pt);\n",
+"Ptw=10^(Pt/10)*1000;\n",
+"printf('\n Transmitter Power = %0.0f microW',Ptw);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.50: Calculate_the_collision_length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 12\n",
+"//page no 542\n",
+"//ex 12_50\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"m=3;\n",
+"n=1;\n",
+"Tb=100;         //ps\n",
+"l=1;            //nm\n",
+"D=0.07;         //ps/nm^2*km\n",
+"lmn=1;          //nm\n",
+"lmo=2;          //nm\n",
+"Do=0.1;         //ps/nm-km\n",
+"Lc=4*Tb/[5*D*lmn*(lmn+2*lmo)];//Collision length  in km\n",
+"printf('\n Collision length without dispersion slope compensation = %0.1f km\n',Lc);//result\n",
+"Lc2=2*Tb/[5*Do*lmn];//Collision length in km\n",
+"printf('\n Collision length with dispersion slope compensation = %0.0f km',Lc2);//result\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.51: Compute_the_soliton_collision_length.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 12\n",
+"//page no 542\n",
+"//ex 12_51\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"Zr=200;         //in km\n",
+"S=4;\n",
+"Ltot1=2*Zr*(S-1);       //total solition collion length in km\n",
+"printf('\n Total solition Collisions length With DSC ,Ltotal = %0.0f km\n',Ltot1);//Result\n",
+"Ltot2=(2/5)*Zr*(S-1);        //total solition collion length in km\n",
+"printf('\n Total solition Collisions length With non-DSC ,Ltotal = %0.0f km\n',Ltot2);//result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.5: Calculate_PIN_diode_required_operating_power_and_total_power_budget.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 12\n",
+"//page no 433\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Is=0.5;         //in A/W\n",
+"Ir=1.5;         //in microA\n",
+"Xw=Ir/Is;\n",
+"printf('\n Electrical power required by PIN diode is = %0.0f microW',Xw);\n",
+"Pxw=10*log10(Xw/10^3);\n",
+"printf('\n Therefore, Electrical power required by PIN diode is = %0.1f dBm',Pxw);\n",
+"\n",
+"Ps=3;            //in dB for safety margin\n",
+"Tp=5;           //in dB\n",
+"Pt=Tp+Ps+Pxw;\n",
+"printf('\n Total Power Required = %0.1f dBm',Pt);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.6: Calculate_maximum_link_distance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 442\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"fb=1.25;            //in Gb/s\n",
+"D=17;           //in ps/nm.km\n",
+"dL=0.5;     //in nm\n",
+"Lmax=1/fb/10^9/dL/10^-9/D/10^-12*10^-9;\n",
+"printf('\n Maximum Link span,Lmax = %0.0f km',Lmax);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.7: Compute_chromatic_dispersio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 442\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"fb=2.5;            //in Gb/s\n",
+"Lmax=50;           //in km\n",
+"dL=0.4;     //in nm\n",
+"D=1/fb/10^9/dL/10^-9/Lmax/10^-12*10^-9;\n",
+"printf('\n Maximum allowable dispersion,D = %0.0f ps/nm-km',D);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.8: Compute_maximum_bit_rate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 443\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Lmax=60;            //in km\n",
+"D=17;           //in ps/nm.km\n",
+"dL=0.5;     //in nm\n",
+"fb=1/Lmax/10^9/dL/10^-9/D/10^-12*10^-9;\n",
+"printf('\n Maximum system bit rate,fb = %0.2f Gb/s',fb);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 12.9: Compute_Maximum_link_span.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 12\n",
+"//page no 443\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"c1=4;               //channel1\n",
+"c2=8;               //channel2\n",
+"c3=16;               //channel3\n",
+"fb=2.5;            //in Gb/s\n",
+"Lmax1=6.1*10^3/(c1*fb)^2;\n",
+"printf('\n Maximum Link span for %0.0f channel, Lmax = %0.0f km \n',c1,Lmax1);\n",
+"Lmax2=6.1*10^3/(c2*fb)^2;\n",
+"printf('\n Maximum Link span for %0.0f channel, Lmax = %0.2f km \n',c2,Lmax2);\n",
+"Lmax3=6.1*10^3/(c3*fb)^2;\n",
+"printf('\n Maximum Link span for %0.0f channel, Lmax = %0.1f km \n',c3,Lmax3);"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/13-Networks.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/13-Networks.ipynb
new file mode 100644
index 0000000..037186b
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/13-Networks.ipynb
@@ -0,0 +1,154 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 13: Networks"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 13.1: Calculate_R9_R7_R8_C4.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 13\n",
+"//page no 568\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Vcc=5;                  //in V\n",
+"Vf=1.5;             //in V\n",
+"If=60;              //in mA\n",
+"B=3.97;\n",
+"N=3;\n",
+"R9=(Vcc-Vf)*(B+1)/If/10^-3;\n",
+"printf('\n R9 = %0.0f ohm\n',R9);\n",
+"R7=R9/2/B-3/N;\n",
+"printf('\n R7 = %0.1f ohm\n',R7);\n",
+"R8=R9/2/B;\n",
+"printf('\n R8 = %0.1f ohm\n',R8);\n",
+"C4=2*10^-9/R8;\n",
+"printf('\n C4 = %0.0f pF',C4*10^12);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 13.2: Calculate_Led_If_R3_C4.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 13\n",
+"//page no 569\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Vu3=1.24;           //in V\n",
+"Vbeq3=0.7;          //in V\n",
+"Vbeq4=0.7;          //in V\n",
+"R5=17.5;            //in Ohm\n",
+"R6=17.5;            //in Ohm\n",
+"Voh=5;          //in V\n",
+"Vol=0;          //in V\n",
+"If=(Vu3-Vbeq3)/R5+(Vu3-Vbeq4)/R6;\n",
+"printf('\n If= %0.1f mA\n',If*1000);\n",
+"R3=(Voh-Vol)/If;\n",
+"printf('\n R3= %0.0f ohm\n',R3);\n",
+"C4=2*10^-9/R3;\n",
+"printf('\n C4= %0.0f pF\n',C4*10^12);\n",
+"//Chapter 13\n",
+"//page no 581\n",
+"//given\n",
+"disp('Page number 581 again  Example 13-2 (numbering mistake)')\n",
+"Er=4.9;\n",
+"h=5;                //in mils\n",
+"w=10;                //in mils\n",
+"t=0.5;                //in mils\n",
+"Z=60/sqrt(0.475*Er+0.67)*log(4*h/0.67/(0.8*w+t));\n",
+"printf('\n Z = %0.1f ohm\n',Z);\n",
+"tpd=1.017*sqrt(0.475*Er+0.67);\n",
+"printf('\n tpd = %0.2f ns/ft\n',tpd);\n",
+"Tpd=tpd*1000/12;           //converted into ps/in\n",
+"printf('\n tpd = %0.2f ps/in\n',Tpd);\n",
+"Co=Tpd/Z;\n",
+"printf('\n Co = %0.1f pF/in\n',Co);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 13.3: Characteristic_impedance_and_propagation_delay.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 13\n",
+"//page no 583\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Er=4.7;\n",
+"b=10;                //in mils\n",
+"w=4;                //in mils\n",
+"t=0.5;                //in mils\n",
+"Z=60/sqrt(Er)*log(4*b/0.67/%pi/(0.8*w+t));\n",
+"printf('\n Z = %0.2f ohm\n',Z);\n",
+"tpd=1.017*sqrt(Er);\n",
+"printf('\n tpd = %0.1f ns/ft\n',tpd);\n",
+"Tpd=tpd*1000/12;           //converted into ps/in\n",
+"printf('\n Also,tpd = %0.0f ps/in\n',Tpd);//answer is slightly different due to rounding off "
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/2-Fundamental_of_Semi_Conductor_Theory_.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/2-Fundamental_of_Semi_Conductor_Theory_.ipynb
new file mode 100644
index 0000000..4a4aa12
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/2-Fundamental_of_Semi_Conductor_Theory_.ipynb
@@ -0,0 +1,337 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 2: Fundamental of Semi Conductor Theory "
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.1: maximum_number_of_electron.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 2\n",
+"//page no 43\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"n=1;\n",
+"Ne=2*n^2;\n",
+"printf('\n Maximum number of electron in 1st shell is %.0f\n ',Ne);//Result\n",
+"n2=2;// shell no\n",
+"Ne2=2*n2^2;// shell no\n",
+"printf('\n Maximum number of electron in 2nd shell is %.0f ',Ne2);//Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.2: Find_band_gap_energy.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 2\n",
+"//page no 45\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"//Given  for silicon for temp 0-400K\n",
+"Eg0_Si=1.17;       //in eV\n",
+"A=4.73*10^-4;       //in eV/K\n",
+"B=636;\n",
+"for i=1:8\n",
+"T=50*i;      //degree/Kelvin\n",
+"Eg_Si=Eg0_Si-(A*T^2)/(B+T);\n",
+"printf('\n Band gap energy of silicon at %.0f K is %.3f eV ',T,Eg_Si);//result\n",
+"end\n",
+"//Given  for Germanium for temp 0-400K\n",
+"disp('');\n",
+"Eg0_Ge=0.7437;       //in eV\n",
+"A_Ge=4.774*10^-4;       //in eV/K\n",
+"B_Ge=235;\n",
+"for i=1:8\n",
+"T=50*i;      //degree/Kelvin\n",
+"Eg_Ge=Eg0_Ge-(A_Ge*T^2)/(B_Ge+T);\n",
+"printf('\n Band gap energy of germanium at %.0f K is %.3f eV ',T,Eg_Ge);//result\n",
+"end\n",
+"\n",
+"//Given  for GaAs for temp 0-400K\n",
+"disp('');\n",
+"Eg0_Ga=1.519;       //in eV\n",
+"A_Ga=5.405*10^-4;       //in eV/K\n",
+"B_Ga=204;\n",
+"for i=1:8\n",
+"T=50*i;      //degree/Kelvin\n",
+"Eg_Ga=Eg0_Ga-(A_Ga*T^2)/(B_Ga+T);\n",
+"printf('\n Band gap energy of GaAs at %.0f K is %.3f eV ',T,Eg_Ga);//result\n",
+"end"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.3: Find_carrier_velocity_and_current_density.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 2\n",
+"//page no 52\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"l=10*10^-3;         //in m\n",
+"w=2*10^-3;         //in m\n",
+"h=2*10^-3;         //in m\n",
+"V=12;           //in V\n",
+"u_n=0.14;         //in  m*m/V*s\n",
+"u_p=0.05;          //in m*m/V*s\n",
+"q_n=1.6*10^-19;     //in Columbs\n",
+"q_p=1.6*10^-19;     //in Columbs\n",
+"p_i=2.4*10^19;     //in columbs\n",
+"n_i=2.4*10^19;     //in columbs\n",
+"E=V/l;\n",
+"v_n=E*u_n;\n",
+"v_p=E*u_p;\n",
+"J_n=n_i*q_n*v_n;\n",
+"J_p=p_i*q_p*v_p;\n",
+"J=J_n+J_p;\n",
+"printf('\n Electron velocity :vn is  %.0f m/s ',v_n);//result\n",
+"printf('\n Hole velocity :vp is  %.3f km/s ',v_p/1000);  // result\n",
+"printf('\n Current density : Jn %0.2f A/m^2',J);             //Result\n",
+"A=88*10^-6;\n",
+"I_T=J*A;\n",
+"printf('\n Total current :I_T is  %.0f mA ',I_T*1000);      //Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.4: Find_electron_density_and_type_of_semi_conductor_and_extrensic_semiconductivity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 2\n",
+"//page no 53\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"n_i=2*10^17;          //electron/m*m*m\n",
+"p=5.7*10^20;            //holes/m*m*m\n",
+"u_n=0.14;         //in  m*m/V*s\n",
+"u_p=0.05;          //in m*m/V*s\n",
+"q_n=1.6*10^-19;     //in Columbs\n",
+"q_p=1.6*10^-19;     //in Columbs\n",
+"n=(n_i)^2/p;\n",
+"mprintf('\n Electron :n is  %e electrons ',n);//result\n",
+"n=7*10^13\n",
+"P=(n*u_n*q_n)+(p*u_p*q_p);\n",
+"printf('\n Conductivity :P is  %.2f S/m ',P);// result\n",
+"// answer misprinted"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.5: Find_barrier_voltage.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 2\n",
+"//page no 55\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"NA=10^22;           //acceptors/m*m*m\n",
+"ND=1.2*10^21;       //donors/m*m*m\n",
+"T=298;             //in Kelvin\n",
+"k=1.38*10^-23;      //Boltzman Constant in J/K\n",
+"q=1.6*10^-19;      //  charge of electron  in C\n",
+"Vt=k*T/q;      //thermal voltage  in V\n",
+"printf('\n VT is  %0.1f mV \n',Vt*1000);     // result\n",
+"n_i=2.4*10^17;      //carrier/m^3 for silicon \n",
+"VB=Vt*log(NA*ND/n_i^2);// barrier voltage in V\n",
+"printf('\n Barrier Voltage of Silicon VB is  %0.0f mV ',VB*1000);     //result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.6: Calculate_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 2\n",
+"//page no 56\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"Is=0.12;          //in pAmp\n",
+"V=0.6;          //in V\n",
+"T=293;             //in Kelvin\n",
+"k=1.38*10^-23;      //Boltzmann's Constant in J/K\n",
+"q=1.6*10^-19;     // charge of electron in C\n",
+"Vt=k*T/q;       //thermal voltage\n",
+"printf('\n VT(20 deg Cel) is  %0.5f V \n',Vt);//result in book is misprint\n",
+"T1=373;             //in Kelvin\n",
+"n=1.25;\n",
+"Vt1=k*T1/q;      //thermal voltage\n",
+"printf('\n VT(100 deg Cel) is  %0.5f V \n',Vt1);\n",
+"I=Is*(exp(V/(n*Vt1))-1);        //forward biasing current in mircoA\n",
+"printf('\n I(100 deg Cel) is  %0.2f microA \n',I/10^6);//result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.7: compute_saturation_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 2\n",
+"//page no 56\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"Is=100;          //in nAmp        \n",
+"Ts=100;             //in Kelvin\n",
+"I_s=Is*10^-9*2^(Ts/10);       //I_s will be in nm \n",
+"printf('\n I(100 deg Cel) is  %0.2f microA \n',I_s*10^6);   //converted to microA from nm\n",
+"// wrong calculation in the book"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 2.8: calculate_radiative_minority.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 2\n",
+"//page no 59\n",
+"//given\n",
+"clc;\n",
+"clear ;\n",
+"Br_Si=1.79*10^-15;           //Recombination coefficient for Si\n",
+"Br_Ge=5.25*10^-14;           //Recombination coefficient for Ge\n",
+"Br_GeAs=7.21*10^-10;           //Recombination coefficient for GeAs\n",
+"Br_InAs=8.5*10^-11;           //Recombination coefficient for InAs\n",
+"P_N=2*10^20;        //per cubic cm\n",
+"T_Ge=1/Br_Ge/P_N;//radiative minority carrier lifetime\n",
+"printf('\n T_Ge is  %0.3f micro-s \n',T_Ge/10^-6);//result\n",
+"T_Si=1/Br_Si/P_N;//radiative minority carrier lifetime\n",
+"printf('\n T_Si is  %0.2f micro-s \n',T_Si/10^-6);//result\n",
+"T_InAs=1/Br_InAs/P_N;//radiative minority carrier lifetime\n",
+"printf('\n T_InAs is  %0.0f ps \n',T_InAs/10^-12);//result\n",
+"T_GeAs=1/Br_GeAs/P_N;//radiative minority carrier lifetime\n",
+"printf('\n T_GeAs is  %0.0f ps \n',T_GeAs/10^-12);//result\n",
+""
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/3-Optical_Sources_.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/3-Optical_Sources_.ipynb
new file mode 100644
index 0000000..aa895e7
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/3-Optical_Sources_.ipynb
@@ -0,0 +1,286 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 3: Optical Sources "
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.1: Determine_the_power_coupled_into_fiber.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 3\n",
+"//page no 67\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Pin=1;      //microW\n",
+"W=15;           //in degree\n",
+"NA=sin(W*%pi/180);\n",
+"NAA=0.26;           //NA=0.2588190 which is rounded off\n",
+"C_c=(NAA)^2;\n",
+"printf('\n Coupling coefficient is  %0.4f  \n',C_c);\n",
+"Pf=C_c*Pin;\n",
+"printf('\n Power coupled into fiber  %0.1f  nW\n',Pf*1000);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.2: Power_Coupled_into_fiber.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 3\n",
+"//page no 67\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"n=0.02;         //in percentage\n",
+"W=20;           //in degree\n",
+"Vf=1.5;         //in Volts\n",
+"If=20;          //in mAmps\n",
+"Pin=If*Vf;\n",
+"printf('\n Power coupled into fiber ,Pin = %0.0f  mW\n',Pin);\n",
+"Po=n*Pin;\n",
+"printf('\n Output Power of the optical source is   %0.1f  mW\n',Po);\n",
+"///from nc=20 degree\n",
+"C_c=(sin(W*%pi/180))^2;\n",
+"Pf=C_c*Po\n",
+"printf('\n Optical power coupled into fibre is ,Pf = %0.0f  microW\n',Pf*1000);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.3: Bandwidth_of_Led_Source.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 3\n",
+"//page no 68\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"tr=10;          //in nsec\n",
+"BW=0.35/tr/10^-9;\n",
+"printf('\n Maximum operating bandwidth is %0.0f  MHZ\n',BW/10^6);    //divided by 10^6 to convert answer in MHZ"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.4: Coupling_efficiency_of_an_optical_source.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 3\n",
+"//page no 70\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"T=1; //Air\n",
+"NA=0.3;\n",
+"n0=1;\n",
+"//x=y;\n",
+"disp('for step index :A=infinite');\n",
+"//for infinite alpha\n",
+"//nc=T*(NA/n0)^2*(x/y)^2*(A/(A+2))\n",
+"nc=T*(NA/n0)^2*(1)^2*1;         // A/(A+2)=1 for A=infinite\n",
+"printf('\n Coupling Coefficient,nc = %0.0f percent \n\n',nc*100);\n",
+"\n",
+"disp('for graded index :A=2');\n",
+"A=2;\n",
+"//n_c=(T*(NA/n0)^2*[A+[1-(y/x)^2]]/(A+2))\n",
+"n_c=(T*(NA/n0)^2*[A+[1-(1)^2]]/(A+2))       //x/y=1\n",
+"printf('\n Coupling Coefficient,nc = %0.1f percent \n',n_c*100);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.5: Coupling_efficiency.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 3\n",
+"//page no 71\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"T=1; //Air\n",
+"NA=0.3;\n",
+"n0=1;\n",
+"A=2;\n",
+"//y=0.75x;\n",
+"disp('for step index :');\n",
+"//for infinite alpha\n",
+"//nc=T*(NA/n0)^2*(x/y)^2*(A/(A+2))\n",
+"nc=T*(NA/n0)^2*(1/0.75)^2*A/(A+2);          //    y/x=0.75\n",
+"printf('\n Coupling Coefficient,nc = %0.0f percent \n\n',nc*100);\n",
+"\n",
+"disp('for graded index :A=2');\n",
+"A=2;\n",
+"//n_c=(T*(NA/n0)^2*[A+[1-(y/x)^2]]/(A+2))\n",
+"n_c=(T*(NA/n0)^2*[A+[1-(0.75)^2]]/(A+2))       //y/x=0.75\n",
+"printf('\n Coupling Coefficient,nc = %0.1f percent \n',n_c*100);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.6: MTBF_of_LED_source.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 3\n",
+"//page no 72\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"//calculate Tf\n",
+"If=85;          //in mAmps\n",
+"Vf=2.5;         //in Volts\n",
+"Ta=25;           //in deg C\n",
+"//calculate Tj\n",
+"W=150;          //in C/W for hermetric led\n",
+"Pd=If*Vf;\n",
+"Tj=Ta+W*Pd/1000;\n",
+"printf('\n Value of Tj is %0.1f deg C\n',Tj);\n",
+"TF=8.01*10^12 *%e^-(8111/(Tj+273));\n",
+"printf('\n Value of TF is %0.0f deg C\n',TF);\n",
+"//calculate RF\n",
+"BF=6.5*10^-4;               //from table\n",
+"QF=0.5;                     //from table\n",
+"EF=1;                       //from table\n",
+"RF=BF*TF*EF*QF*1/10^6;\n",
+"disp(RF,'Value of RF')\n",
+"printf('\n Value of MTBF is %0.0f*10^6 hours \n',1/RF/10^6);//Answer in book is misprint in last line\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 3.7: Calculate_MTBF.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 3\n",
+"//page no 74\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"//calculate Tf\n",
+"If=120;          //in mAmps\n",
+"Vf=1.8;         //in Volts\n",
+"Ta=80;           //in deg C\n",
+"//calculate Tj\n",
+"W=150;          //in C/W for hermetric led\n",
+"Pd=0.5*If*Vf;\n",
+"Tj=75+W*Pd/1000;\n",
+"printf('\n Value of Tj is %0.1f degree cel \n',Tj);\n",
+"TF=8.01*10^12 *%e^-(8111/(Tj+273));\n",
+"printf('\n Value of TF is %0.0f \n',TF);\n",
+"//calculate RF\n",
+"BF=6.5*10^-4;               //from table\n",
+"QF=0.2;                     //from table\n",
+"EF=0.75;                       //from table\n",
+"RF=BF*TF*EF*QF*1/10^6;\n",
+"printf('\n Value of RF is %0.3f*10^6 \n',RF*10^6);\n",
+"printf('\n Value of MTBF is %0.0f*10^6 hours \n',1/RF/10^6);"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/4-Optical_Detectors.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/4-Optical_Detectors.ipynb
new file mode 100644
index 0000000..1d97346
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/4-Optical_Detectors.ipynb
@@ -0,0 +1,129 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 4: Optical Detectors"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.1: Response_time_of_PIN_photodetector.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 4\n",
+"//page no 99\n",
+"//given\n",
+"clc;\n",
+"Tn=5;               //in micrometer\n",
+"Vs=10^7;          //in m/s\n",
+"tr=Tn*10^-6/Vs;\n",
+"disp('ps',tr/10^-12,'Response time');"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.2: MTBF_of_photodetector.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 4\n",
+"//page no 106\n",
+"//given\n",
+"clc;\n",
+"//calculate Tf\n",
+"Pd=1.15;            //in mW\n",
+"//calculate Tj\n",
+"TA=25;              //in deg C\n",
+"theta_JA=200;          //in C/W for hermetric led\n",
+"TJ=TA+theta_JA*Pd/10^3;\n",
+"TF=8.01*10^12 *%e^-(8111/(TJ+273));\n",
+"printf('\n Value of TJ is %0.2f deg C\n',TJ);\n",
+"printf('\n Value of TF is %0.2f deg C\n',TF);\n",
+"//calculate RF\n",
+"BF=1.1*10^-3;               //from table\n",
+"QF=0.5;                     //from table\n",
+"EF=1;                       //from table\n",
+"RF=BF*TF*EF*QF*1/10^6;\n",
+"disp(RF,'Value of RF');\n",
+"printf('\n Value of MTBF is %0.0f*10^6 hours \n',1/RF/10^6);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 4.3: Photon_Lifetime.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 4\n",
+"//page no 114\n",
+"//given\n",
+"clc;\n",
+"R1=0.7;\n",
+"R2=0.99;\n",
+"ad=0.1;\n",
+"//compute Ld\n",
+"Ld=1-R1*R2*%e^-(2*ad);\n",
+"printf('\n Decay Loss %0.4f \n',Ld);\n",
+"trt=40;//fs\n",
+"tph=trt/Ld;\n",
+"printf('\n Photon lifetime %0.2f fs\n',tph);\n",
+"BW=1/tph;\n",
+"printf('\n Bandwidth %0.1f Thz\n',BW*1000);//Answer in Thz  \n",
+""
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/5-Optical_Amplifiers.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/5-Optical_Amplifiers.ipynb
new file mode 100644
index 0000000..0ddb79f
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/5-Optical_Amplifiers.ipynb
@@ -0,0 +1,84 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 5: Optical Amplifiers"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.1: Input_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 5\n",
+"//page no 128\n",
+"//given\n",
+"clc;\n",
+"Vrms=0.3;     //in V\n",
+"CF=0.75;        //in V/mW\n",
+"Pi=Vrms/CF;         \n",
+"printf('\n input power %0.1f mW\n',Pi);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.2: Compute_pseudo_random_binary_sequence.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 5\n",
+"//page no 131\n",
+"//given\n",
+"clc;\n",
+"Di=155;         //in Mb/s\n",
+"sl=10^-3*Di*10^6;           //in  bitstream\n",
+"//PRBS=2^x-1=sl;\n",
+"x=log(sl+1)/log(2);//equation is made to pick value of x\n",
+"printf('\n PRBS =2^%0.0f -1 \n',x);"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/6-Optical_Transmittor.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/6-Optical_Transmittor.ipynb
new file mode 100644
index 0000000..2d8aa9c
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/6-Optical_Transmittor.ipynb
@@ -0,0 +1,699 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 6: Optical Transmittor"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.10: find_maximum_power_dissipation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"//chapter 6\n",
+"//page no161\n",
+"//exa 6_10\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"vcc=-5;             //in v\n",
+"imod=35;            //in mA\n",
+"ibias=18;           //in mA\n",
+"vbias=-2;           //in v\n",
+"vout=2;             //in v\n",
+"tj=30;            //degree cel\n",
+"icc=140;            //in mA\n",
+"Pt=(-vcc*icc*10^-3)+(-vcc-vout)*imod*10^-3+(-vcc+vbias)*ibias*10^-3;\n",
+"printf('Pt= %0.0f mW',Pt*1000);\n",
+"Tj=30;//in degree\n",
+"Tj_a=Tj*Pt;\n",
+"Tcase=125-Tj_a;//in degree\n",
+"printf('\n Tcase(max)= %0.0f degree Cel',Tcase);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.11: Calculate_differential_and_common_mode_impedance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no-174\n",
+"//Ex6_11\n",
+"//given\n",
+"clear;clc;\n",
+"z11=49.95;            //in ohm\n",
+"z12=0.15;           //in ohm\n",
+"z21=0.15;           //in ohm\n",
+"z22=49.95;          //in ohm\n",
+"zdiff=2*(z11-z12);\n",
+"printf('\n Zdiff= %0.1f ohm',zdiff);        //answer misprinted\n",
+"zcm=z11+z12;\n",
+"printf('\n Zcm= %0.1f ohm',zcm);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.12: Compute_differential_mode_and_common_mode_impedance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no174\n",
+"//Ex6_11\n",
+"//given\n",
+"clear;clc;\n",
+"z11=65.4;//in ohm\n",
+"z12=8.2;//in ohm\n",
+"z21=8.2;//in ohm\n",
+"z22=65.4;//in ohm\n",
+"zdiff=2*(z11-z12);\n",
+"printf('\n Zdiff= %0.1f ohm',zdiff);  \n",
+"zcm=z11+z12;\n",
+"printf('\n Zcm= %0.1f ohm',zcm);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.13: Compute_intermediate_frequency.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no181\n",
+"//Ex6_13\n",
+"//given\n",
+"clear;clc;\n",
+"dV=50;              //in mV\n",
+"di=3;           //in Amp\n",
+"Lcable=15;          //in nH\n",
+"fL=dV*10^-3/di/2/%pi/Lcable/10^-9;\n",
+"printf('fLcable = %0.0f kHz',fL/1000);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.14: Allowed_parasitic_cable_inductance.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no181\n",
+"//Ex6_14\n",
+"//given\n",
+"clear;clc;\n",
+"dV=50;              //in mV\n",
+"di=4;           //in Amp\n",
+"fL=120;         //in kHz\n",
+"Lcable=dV*10^-3/di/2/%pi/fL/10^3;\n",
+"printf('\n The maximum allowed parasitic cable inductance (Lcable) must not exceed %0.1f nH',Lcable*10^9);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.15: Calculate_high_frequency_component.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no182\n",
+"//Ex6_15\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"dV=40;              //in mV\n",
+"di=2.5;           //in Amp\n",
+"Lbypas=0.5;          //in nH\n",
+"fL=dV*10^-3/di/2/%pi/Lbypas/10^-9;\n",
+"printf('fHnoise = %0.1f MHz',fL/10^6);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.16: compute_low_frequency_component.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no182\n",
+"//Ex6_16\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"dV=50;              //in mV\n",
+"di=2.5;           //in Amp\n",
+"Cbypas=220;          //in microF\n",
+"fL=di/(dV*10^-3*2*%pi*Cbypas*10^-6);\n",
+"printf('fLnoise = %0.0f kHz',fL/1000);          //Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.17: Calculate_noise_bandwidth.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no182\n",
+"//Ex6_17\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"dV=50;              //in mV\n",
+"di=4;           //in Amp\n",
+"Cbypas=200;          //in microF\n",
+"Lbypas=0.2;          //in nH\n",
+"fL=di/(dV*10^-3*2*%pi*Cbypas*10^-6);\n",
+"printf('\n fLnoise = %0.0f kHz\n ',fL/1000);          //Result misprinted\n",
+"fH=dV*10^-3/di/2/%pi/Lbypas/10^-9;\n",
+"printf('\n fHnoise = %0.0f MHz\n ',fH/10^6);         \n",
+"Bw=fH-fL;\n",
+"printf('\n Bwnoise = %0.2f MHZ',Bw/10^6);         //Result miscalculated"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.18: Calculate_effective_hight_frequency_component.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no184\n",
+"//Ex6_18\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"dV=40;              //in mV\n",
+"di=3;           //in Amp\n",
+"LT=0.05;          //in nH\n",
+"fH=dV*10^-3/di/2/%pi/LT/10^-9;\n",
+"printf('\n fCdecoupling(high) = %0.1f MHz\n ',fH/10^6);         //Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.19: Calculate_the_effective_low_frequency_component.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no184\n",
+"//Ex6_19\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"dV=45;              //in mV\n",
+"di=2.5;           //in Amp\n",
+"CT=2.2;          //in microF\n",
+"LT=0.05;          //in nH\n",
+"fCL=di/(dV*10^-3*2*%pi*CT*10^-6);\n",
+"printf('\n fLnoise = %0.0f MHz\n ',fCL/10^6);          //Result     \n",
+"fCH=42.3;           //in MHz taken from last question i.e. 6.18\n",
+"printf('\n fHnoise (from last question i.e. 6.18)= %0.1f MHz\n ',fCH);        \n",
+"printf('\n  %0.0fMHz <= B.W.noise <= %0.2fMHZ',fCL/10^6,fCH);         //Result"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.1: Determine_whether_heat_sink_or_not.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 6\n",
+"//page no 139\n",
+"//Given\n",
+"clear;\n",
+"clc;\n",
+"Tj=125;     //in degree celsius\n",
+"Tamp=60;        //n degree celsius\n",
+"Pt=1.8;     //in W\n",
+"RthJ_a =34;         //in k/w(Assumption)\n",
+"Rth=(Tj-Tamp)/Pt;\n",
+"printf('\n Rth = %0.0f K/W',Rth);\n",
+"if Rth>RthJ_a then\n",
+"    printf('\n No Heat sink is required');\n",
+"else\n",
+"    printf('\n Yes,Heat sink is required');\n",
+"end ;    \n",
+"  "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.2: determine_whether_or_not_heat_sink.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 6\n",
+"//page no 140\n",
+"//Given\n",
+"\n",
+"clear;\n",
+"clc;\n",
+"Tj=120;//in degree celsius\n",
+"Tamp=80;//n degree celsius\n",
+"Pt=2.1;//in W \n",
+"RthJ_a =34;         //in k/w(Assumption)\n",
+"Rth=(Tj-Tamp)/Pt;\n",
+"printf('Rth = %0.0f K/W',Rth);\n",
+"if Rth>RthJ_a then\n",
+"    printf('\n No Heat sink is required');\n",
+"else\n",
+"    printf('\n Yes,Heat sink is required');\n",
+"end ; \n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.3: Determine_wheather_heat_sink.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6\n",
+"//page no 140\n",
+"//example 6-3\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"//data insufficient\n",
+"Rth=17.70;           // Rth assumed minimum\n",
+"Rthc_H=0.65;        //k/w\n",
+"Rthj_a=33;          //k/w\n",
+"Rthj_c=3;           //k/w\n",
+"RthH_a=1/(1/Rth-1/Rthj_a)-Rthj_c-Rthc_H;\n",
+"printf('RthH-a <= %0.1f K/W',RthH_a);\n",
+"//disp(RthH_a,'heat sink thermal resistance');"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.4: Find_Junction_Temperature.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter6\n",
+"//page no 148\n",
+"//example 6-4\n",
+"//given\n",
+"clear;clc;\n",
+"Vcc=5;//in volt\n",
+"Icc=24;//in mA\n",
+"Vset=0.65;//in volt\n",
+"Vf=1.5;//in volt\n",
+"IMOD=15;//in mA\n",
+"TA=25;//in degree celsius\n",
+"Pdynamic=(Vcc-Vf-Vset)*Icc;\n",
+"disp('mW',Pdynamic,'Power dissipation under dynamic condition')\n",
+"Pstatic=(Vcc*Icc);\n",
+"disp('mW',Pstatic,'power dissipation under static condition')\n",
+"PD=Pdynamic+Pstatic;\n",
+"disp('mW',PD,'total power dissipation')\n",
+"//Tj=TA+PD*wj_a;\n",
+"TA=25;//in degree cel\n",
+"wj_a=84;//degree cel/w\n",
+"PD=188.4;       //mW\n",
+"Tj=TA+PD*10^-3*wj_a;\n",
+"printf('\n Temp. of junction temp %0.0f degree C',Tj)\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.5: calculate_value_of_r1_r2_r3_and_c1.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no150\n",
+"//exa 6_5Ex6_5\n",
+"//given\n",
+"clc;\n",
+"clear;\n",
+"Ifon=120;               //in mA\n",
+"Vcc=5;      //in V\n",
+"Vfon=2;         //in V\n",
+"R3=(Vcc-Vfon)/Ifon/10^-3 +3.2*(Vcc-Vfon-1.4)/Ifon/10^-3;\n",
+"printf('\n R3= %0.0f ohm',R3);\n",
+"R0=(R3-32)/3.2;\n",
+"printf('\n R0= %0.0f ohm',R0);\n",
+"R1=(R0+10)/2;\n",
+"printf('\n R1= %0.0f ohm',R1);\n",
+"R2=R1-10;\n",
+"printf('\n R2= %0.0f ohm',R2);\n",
+"C1=2*10^-9/R1;\n",
+"printf('\n C1= %0.0f pF',C1*10^12);         //answer in book is approximately written"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.6: Compute_required_reference_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"//chapter 6\n",
+"//page no155\n",
+"//Ex6_6\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"Impd1=250;     //in microA\n",
+"Impd0=25;     //in microA\n",
+"Iref=(1/16)*Impd1*10^-6;\n",
+"printf('\n Reference current is %0.3f microA',Iref*10^6)\n",
+"Rref=1.5/Iref;\n",
+"printf('\n External bias resistor value Rref1is %0.0f kohm',Rref/1000)\n",
+"//or\n",
+"Rref1=24/Impd1/10^-6;\n",
+"printf('\n Also,Rref1=24/Impd \n External bias resistor value is %0.0f kohm',Rref1/1000)\n",
+"Irefz=(1/4)*Impd0;\n",
+"printf('\n Ref0 current is %0.2f microA',Irefz)\n",
+"Rrefz=1.5/Irefz/10^-6;\n",
+"printf('\n External bias resistor value Rrefz is %0.0f kohm',Rrefz/1000)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.7: Find_bandwidth_for_optical_one_and_zero.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no157\n",
+"//Ex 6_7\n",
+"//given\n",
+"clear;\n",
+"clc;\n",
+"R=400;          //in mA\n",
+"nEO=25;         //in mW\n",
+"nlaser=nEO*10^-3*R*10^-3;\n",
+"printf('\n nlaser = %0.2f ',nlaser);\n",
+" Tone=(40*10^-12)*(80*10^3)/nlaser;\n",
+"printf('\n Tone = %0.0f micros ',Tone*10^6);\n",
+" BWone=1/(2*%pi*Tone);\n",
+"printf('\n BWone = %0.0f Hz ',BWone);\n",
+"Tzero=(40*10^-12)*80*10^3/nlaser;\n",
+"BWzero=1/2/%pi/Tzero;        //Hz\n",
+"printf('\n BWzero = %0.0f Hz ',BWzero);\n",
+"//answer misprinted"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.8: compute_external_resistance_and_alarm_current.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no159\n",
+"//exa 6_8\n",
+"//given\n",
+"clear;clc;\n",
+"iol =5;       //in mA\n",
+"ioh=80;         //bias current in mA\n",
+"ralarmH=(1.5*1500)/ioh/10^-3;\n",
+"printf('\n Alarm resistor RalarmH is %0.0f kOhm',ralarmH/1000);\n",
+"ralarmL=(1.5*300)/iol/10^-3;\n",
+"printf('\n Alarm resistor RalarmL is %0.0f kOhm',ralarmL/1000);\n",
+"ialarmh=80*10^-3;\n",
+"ialarmH=ioh*10^-3/1500;\n",
+"printf('\n Alarm current  IalarmH is %0.0f microA',ialarmH*10^6);  //unit of anwer misprinted in book\n",
+"ialarml=5*10^-3;\n",
+"ialarmL=iol*10^-3/300;\n",
+"printf('\n Alarm current  IalarmL is %0.0f microA',ialarmL*10^6);\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 6.9: Total_power_dissipatio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//chapter 6\n",
+"//page no160\n",
+"//exa 6_9\n",
+"//given\n",
+"clear;clc;\n",
+"Ibias=15;       //in mA  assumption\n",
+"Ild=35;         //in mA\n",
+"Rld=50;         //in ohm\n",
+"Ildi=100;         //in mA\n",
+"Ilde=50;         //in mA\n",
+"Imod=(Ildi+Ilde)/Ildi*35;  //mA\n",
+"printf('Total modulation current is \nImod=%.2f mA\n',Imod);\n",
+"Ildq=1.2/100*10^3;            //in mA  \n",
+"printf('The current complementary output is \nIldq=%.1f mA\n',Ildq);\n",
+"Vld=-1.2-Rld*(Ibias+Ild)*10^-3;       //optical high\n",
+"printf('The laser voltage for optical high is \nVld=%.2f V\n',Vld);\n",
+"Vld=-1.2-Rld*(Ibias)*10^-3;           //optical dark\n",
+"printf('The laser voltage for optical dark is \nVld=%.2f V\n',Vld);\n",
+"Vldq=-Ild*10^-3*Rld;\n",
+"printf('The laser voltage at complimentary o/p is \nVldq=%.2f V\n',Vldq);\n",
+"Rchock=5;           //in Ohm\n",
+"Vchock=-Rchock*Ibias*10^-3;\n",
+"printf('\nVchock=%.3f V\n',Vchock);\n",
+"Vbias=0.5*(-3.7+Vld)+Vchock;\n",
+"printf('\nVbias=%.1f V\n',Vbias);\n",
+"\n",
+"//(i) Pdvee1\n",
+"Pdvcc=5*2.5;        //in mW\n",
+"printf('\nPdvcc=%.1f mW\n',Pdvcc);\n",
+"Pdvee1=4.5*80;        //in mW\n",
+"printf('\nPdvee1=%.0f mW\n',Pdvee1);\n",
+"//(ii) Pdvee2\n",
+"Pdvee2=6*160;        //in mW\n",
+"printf('\nPdvee2=%.0f mW\n',Pdvee2);\n",
+"//(iii) PdLD\n",
+"PdLD=0.5*(3.75*50);        //in mW\n",
+"printf('\nPdLD=%.2f mW\n',PdLD);\n",
+"//(iv) PdLQ\n",
+"PdLDQ=0.5*abs(Vld)*50;        //in mW\n",
+"printf('\nPdLDQ=%.2f mW\n',PdLDQ);\n",
+"//(v) PdLDQ\n",
+"Pdbias=abs(Vbias)*Ibias;        //in mW\n",
+"printf('\nPdbias=%.1f mW\n',Pdbias);\n",
+"//PT\n",
+"PT=Pdvcc+Pdvee1+Pdvee2-[PdLD+PdLDQ+Pdbias];\n",
+"printf('\nTotal power dissipation (PT)=%.1f mW\n',PT);"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/7-Optical_Receivers_.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/7-Optical_Receivers_.ipynb
new file mode 100644
index 0000000..b16f9c8
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/7-Optical_Receivers_.ipynb
@@ -0,0 +1,126 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 7: Optical Receivers "
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.1: PWD_of_optical_receiver.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 7\n",
+"//page no 203\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Trec=54;          //in ns\n",
+"Ttrans=40;          //in ns\n",
+"Pwd=(Trec-Ttrans)/Ttrans*100;\n",
+"printf('\n PWD= %0.0f percent',Pwd) "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.2: Value_of_Radj.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 7\n",
+"//page no 214\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"//Vc=Vdin-Vdinq\n",
+"Vc=5;           //in mV  Vdin-Vdinq=Vc\n",
+"Irset =1.8*10^-3*(Vc*10^-3);     //in A\n",
+"printf('\n Irset %0.0f microA',Irset*10^6) ;\n",
+"Vs=1.5;              //Voltage at signal level below Vcc in V\n",
+"Radj=Vs/Irset;                 //in Ohm\n",
+"printf('\n Radj %0.0f kohm',Radj*10^-3) ;\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 7.3: Reference_voltage_and_reference_resistor.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 7\n",
+"//page no 223\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"\n",
+"Rl=50;      //in Ohm\n",
+"Ro=100;     //in Ohm\n",
+"Vos=450;            //in mV\n",
+"Vref=(Rl+Ro)/Rl*Vos/2;\n",
+"printf('\n Vref= %0.0f mV',Vref) ;\n",
+"Vee=3.3;            //in V\n",
+"R1=500;         //in Ohm\n",
+"R2=16000;            //in Ohm\n",
+"//Rref=(Vee/Vref/10^3-1)*R1/[1-{R1/R2*(Vee/Vref/10^3-1)}]\n",
+"Rref={(Vee/Vref/10^-3-1)*R1}/[1-R1/R2*(Vee/Vref/10^-3-1)]\n",
+"printf('\n Rref= %0.0f kohm',Rref) ;\n",
+"printf('\n Approx. Rref= %0.1f kohm',Rref*10^-3) ;\n",
+""
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}
diff --git a/Fiber_Optics_Communication_by_H_Kolimbiris/9-Optical_Fibers.ipynb b/Fiber_Optics_Communication_by_H_Kolimbiris/9-Optical_Fibers.ipynb
new file mode 100644
index 0000000..ced7cdf
--- /dev/null
+++ b/Fiber_Optics_Communication_by_H_Kolimbiris/9-Optical_Fibers.ipynb
@@ -0,0 +1,976 @@
+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 9: Optical Fibers"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.10: Raman_scattering_threshold_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 305\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=850;          //in nm\n",
+"L1=L/1000;           //converted L in micrometer for using in given formula\n",
+"A=0.4;          //in dB/km\n",
+"d=5;        //in micrometer\n",
+"Po=5.9*10^-2*A*L1*d^2;\n",
+"printf(' \n Po(Th) =  %0.0f mW',Po*1000);       //rounding off error"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.11: Raman_scattering_threshold_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 305\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=1330;          //in nm\n",
+"L1=L/1000;           //converted L in micrometer for using in given formula\n",
+"A=0.4;          //in dB/km\n",
+"d=5;        //in micrometer\n",
+"Po=5.9*10^-2*A*L1*d^2;\n",
+"printf(' \n Po(Th) =  %0.0f mW',Po*1000);       //unit in book is wrong"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.12: Raman_sscattering_threshold_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 9\n",
+"//page no 305\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=1550;          //in nm\n",
+"L1=L/1000;           //converted L in micrometer for using in given formula\n",
+"A=0.4;          //in dB/km\n",
+"d=5;        //in micrometer\n",
+"Po=5.9*10^-2*A*L1*d^2;\n",
+"printf(' \n Po(Th) =  %0.0f mW',Po*1000);       //unit in book is wrong"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.13: Maximum_modal_number.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 310\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"R=25;           //in nm\n",
+"R1=25*10^-6;            //in m\n",
+"L=1000;                 //in nm\n",
+"L1=10^-6;           //in m\n",
+"NA=0.2;     \n",
+"V=2*%pi/L1*R1*NA;\n",
+"printf(' \n Normalised frequency(V) =  %0.1f ',V);\n",
+"y=2;                //for parabolic\n",
+"Mmax=y/(y+2)*(V^2)/2;\n",
+"printf(' \n Maximum number of modes is equal to =  %0.0f ',Mmax);//answer in book is wrong\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.14: Maximum_operating_bandwidth.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 313\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Tp=0.25;           //in microsec\n",
+"fB=0.529/Tp/10^-6;      //channel bitrate\n",
+"fBw=fB;             //channel bandwidth = channel bitrate when zero ISI and RZ input data is modulated\n",
+"printf(' \n Maximum operating bandwidth =  %0.3f MHz',fBw*10^-6);\n",
+"L=50;           //in km\n",
+"D=Tp*10^-6/L;   //Dispersion\n",
+"printf(' \n Dispersion =  %0.0f ns/km',D*10^9);\n",
+"fBwL=fBw*10^-6*L;            //bandwidth length product\n",
+"printf(' \n Bandwidth length product(fBw*L) =  %0.1f MHz/km',fBwL);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.15: Maximum_operating_bandwidth.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 314\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Tp=2;           //in microsec\n",
+"fB=0.529/Tp/10^-6;  //channel bit rate\n",
+"fBw=fB;             //channel bandwidth = channel bitrate when zero ISI and RZ input data is modulated\n",
+"printf(' \n Maximum operating bandwidth =  %0.2f MHz',fBw*10^-6);\n",
+"L=50;           //in km\n",
+"D=Tp*10^-6/L;   //Dispersion\n",
+"printf(' \n Dispersion =  %0.0f ns/km',D*10^9);     //unit in book is wrong\n",
+"fBwL=fBw*10^-6*L;         //bandwidth length product\n",
+"printf(' \n Bandwidth length product(fBw*L) =  %0.0f MHz/km',fBwL);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.16: Maximum_operating_bandwidth.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 314\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Tp=5;           //in microsec\n",
+"fB=0.529/Tp/10^-6;   //channel bit rate\n",
+"fBw=fB;             //channel bandwidth = channel bitrate when zero ISI and RZ input data is modulated\n",
+"printf(' \n Maximum operating bandwidth =  %0.3f MHz',fB*10^-6);\n",
+"L=50;           //in km\n",
+"D=Tp*10^-6/L;   //Dispersion\n",
+"printf(' \n Dispersion =  %0.1f micro sec/km',D*10^6);\n",
+"fBwL=fBw*10^-6*L;        //bandwidth length product\n",
+"printf(' \n Bandwidth length product(fBw*L) =  %0.1f MHz/km',fBwL);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.17: RMS_pulse_chirping.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 315\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Slw=25;         //in nm\n",
+"L=850;          //in nm         given\n",
+"c=3*10^5;        //in km/s\n",
+"ofmd=0.02;          //optical fiber material dispersion\n",
+"Mdp=1/L/c*ofmd;         //answer mismatch due to differnt value chosen for calculation\n",
+"printf(' \n Material Dispersion parameter Mdp =  %0.0f ps/nm.km',Mdp*10^12);\n",
+"l=1;            //in km\n",
+"dmd=Slw*l*Mdp;      //pulse chirping\n",
+"printf(' \n pulse chirping dmd =  %0.2f ns/km',dmd*10^9);\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.18: RMS_pulse_broadening.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 315\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Slw=2;         //in nm\n",
+"L=850;          //in nm         given\n",
+"c=3*10^5;        //in km/s\n",
+"ofmd=0.02;          //optical fiber material dispersion\n",
+"Mdp=1/L/c*ofmd;   //answer mismatch due to differnt value chosen for calculation\n",
+"printf(' \n Material Dispersion parameter Mdp =  %0.0f ps/nm.km',Mdp*10^12);\n",
+"l=1;            //in km\n",
+"dmd=Slw*l*Mdp;\n",
+"printf(' \n pulse chirping dmd =  %0.3f ns/km',dmd*10^9);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.19: Channel_capacity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 325\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"fb1=2.5;            //in Gb/s\n",
+"D1=20;          //in ps/nm.km\n",
+"D2=5;          //in ps/nm.km\n",
+"fb2=D1/D2*fb1;      \n",
+"printf('\n fb2 = %0.0f Gb/s(OC-192)',fb2)\n",
+"//Values of D1 and D2 are conflicted in question ,however solution is correct "
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.1: Compute_angle_of_acceptance_critical_angle_and_NA.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 296\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"n2=1.35;            //refractive index\n",
+"n1=1.4;            //refractive index\n",
+"Wo=asind(n2/n1);             //in radians\n",
+"printf('\n Critical Angle,Wo = %0.2f degree\n',Wo);\n",
+"NA=sqrt(n1^2-n2^2);\n",
+"printf('\n Numerical Aperture,NA = %0.2f \n',NA);\n",
+"Wa=asind(NA);                //in radians\n",
+"printf('\n Angle of acceptance,Wa = %0.2f degree\n',Wa);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.20: Channel_capacity.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 325\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"fb1=2.5;            //in Gb/s\n",
+"DV1=100;          //in GHz\n",
+"DV2=50;          //in GHz\n",
+"fb2=DV1/DV2*fb1;\n",
+"printf('\n fb2 = %0.0f Gb/s',fb2)"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.21: Total_chromatic_dispersio.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 332\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=400;          //in km\n",
+"dAV=4;          //in ps/km\n",
+"dTL=L*dAV;      //total chromatic dispersion\n",
+"printf('dTL =%0.0f ps/nm.km',dTL);\n",
+"printf('\n or,dTL =%0.1f ns/nm.km',dTL/10^3);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.22: Compute_optical_attenuation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 335\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"no=1;            //refractive index\n",
+"n1=1.35;            //refractive index\n",
+"Po=[(n1-no)/(n1+no)]^2;     //fresnal reflection\n",
+"printf('\n Po(refl)= %0.3f',Po);\n",
+"Lrefl=-10*log10(1-Po);      //attenuation loss\n",
+"printf('\n L(refl)= %0.1f dB',Lrefl);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.23: Compute_total_attenuation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 335\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"no=1;            //refractive index\n",
+"n1=1.55;            //refractive index\n",
+"Po=[(n1-no)/(n1+no)]^2;    //fresnal reflection\n",
+"printf('\n Fresnel reflective coefficient,Po(refl)= %0.5f\n',Po);\n",
+"Lrefl=-10*log10(1-Po);     //attenuation loss\n",
+"printf('\n Attenuation based on Fresnel reflective coefficient,L(refl)= %0.1f dB\n',Lrefl);\n",
+"Ltot=5*Lrefl;\n",
+"printf('\n Total link attenuation on Fresnel reflections,Ltotal = %0.1f dB',Ltot);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.24: Compute_the_insertion_loss.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 336\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"n1=1;\n",
+"n2=1.5;\n",
+"a=25;           //in micrometer\n",
+"y=3;          //in micrometer\n",
+"Csim=16*(n1/n2)^2/%pi/[1+(n1/n2)]^4*[2*acos(y/2/a)-(y/a)*[1-(y/2/a)^2]^0.5];  \n",
+"//lateral coupling coefficient\n",
+"a=2*acos(y/2/a)-(y/a)*sqrt(1-(y/2/a)^2);\n",
+"b=16*(n1/n2)^2/%pi/[1+(n1/n2)]^4;\n",
+"printf('\n Lateral  coupling coefficient,Csim= %0.2f\n',Csim);\n",
+"Lsim=-10*log10(1-Csim);\n",
+"printf('\n Insertion Loss,Lsim= %0.1f dB\n',Lsim);\n",
+"//Answer wrong in book"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.25: Compute_insertion_loss.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 337\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Alpha=2;\n",
+"a=25;           //in micrometer\n",
+"y=2;            //in micrometer\n",
+"Cgim=2/%pi*(y/a)*(Alpha+2)/(Alpha+1);       //lateral coupling coefficient\n",
+"printf('\n Csim= %0.3f\n',Cgim);\n",
+"Lgim=-10*log10(1-Cgim);     //insertion loss\n",
+"printf('\n Insertion Loss,Lgim= %0.1f dB\n',Lgim);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.26: Compute_insertion_loss.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 339\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"n1=1.5;            //refractive index\n",
+"n2=1.5;            //refractive index\n",
+"W=2.5;      //in degree\n",
+"NA1=0.3;\n",
+"NA2=0.4;\n",
+"Csim1=16*(n1/n2)^2/[1+(n1/n2)^4]*[1-n2*W/(180*NA1)];   //angular coupling coefficient\n",
+"//Answer wrong in book\n",
+"printf('\n Csim= %0.3f\n',Csim1);\n",
+"Lsim1=-10*log10(Csim1);\n",
+"printf('\n Insertion Loss,Lsim= %0.3f dB\n',Lsim1);\n",
+"Csim2=16*(n1/n2)^2/[1+(n1/n2)^4]*[1-n2*W/(180*NA2)]; //angular coupling coefficient\n",
+"//Answer wrong in book\n",
+"printf('\n Csim= %0.3f\n',Csim2);\n",
+"Lsim2=-10*log10(Csim2);\n",
+"printf('\n Insertion Loss,Lsim= %0.2f dB\n',Lsim2);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.27: Compute_total_insertion_loss.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 340\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"a=4;            //in micrometer\n",
+"V=2.4;\n",
+"aw=1;           //in degree\n",
+"NA1=0.2;\n",
+"n1=1.45;            //refractive index\n",
+"y=1;            //in micrometer\n",
+"omega=a*[0.65+1.62*V^-1.5+2.88*V^-6]/sqrt(2);\n",
+"printf('\n Normalised spot view (w)=  %0.2f micrometer',omega);\n",
+"Lsml=2.17*(y/omega)^2;\n",
+"printf('\n Insertion loss due to lateral,Lsm=  %0.2f dB',Lsml);     //answer is wrong in book \n",
+"Lsmg=2.17*(aw*%pi/180*omega*n1*V/a/NA1)^2;\n",
+"printf('\n Insertion loss due to angular,Lsm=  %0.2f dB',Lsmg);\n",
+"\n",
+"printf('\n Total Insertion loss,Lsmtotal=  %0.2f dB',Lsml+Lsmg);\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.28: Compute_insertion_loss_at_the_joint.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 340\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"a1=4.5;            //in micrometer\n",
+"a2=4;            //in micrometer\n",
+"V=2.1;\n",
+"aw=1;           //in degree\n",
+"NA=0.2;\n",
+"n1=1.45;\n",
+"y=1;            //in micrometer\n",
+"w1=a1*[0.65+1.62*V^-0.5+2.88*V^-6]/sqrt(2);     //insertion loss\n",
+"printf('\n Wo1=  %0.1f ',w1);\n",
+"w2=a2*[0.65+1.62*V^-0.5+2.88*V^-6]/sqrt(2);     //insertion loss\n",
+"printf('\n Wo2=  %0.1f ',w2);\n",
+"Lintr=-10*log10(4*[(w1/w2+w2/w1)^-2]);        //toatl insertion loss at joint\n",
+"printf('\n Lintr=  %0.2f dB',Lintr);        //Answer wrong in book"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.2: Fiber_Attenuation.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 300\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Po=8;           //in mW\n",
+"Pi=50;              //in mW\n",
+"l=15;           //in km\n",
+"TA=-10*log10(Po/Pi);\n",
+"printf('\n Total fibre Attenuation,L = %0.2fdB/%0.0fkm \n',TA,l);\n",
+"Alpha=TA/l;     \n",
+"printf('\n Alpha is  = %0.2f dB/km\n',Alpha);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.3: Maximum_length_of_optical_fibre.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 300\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"Po=10;           //in mW\n",
+"Pi=150;              //in mW\n",
+"Alpha=0.8;          //in dB/km\n",
+"TA=-10*log10(Po/Pi);\n",
+"printf('\n Total fibre Attenuation,L = %0.2f dB \n',TA);\n",
+"l=TA/Alpha;\n",
+"printf('\n maximum length is,l = %0.2f km\n',l);\n",
+"//Round off Variations appear"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.4: Rayleigh_attenuation_of_an_optical_fibre.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"//Chapter 9\n",
+"//page no 302\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"B=92*10^-12;            //in m^2/N\n",
+"Tf=1550;        //in K\n",
+"n=1.46;            //refractive index\n",
+"p=0.29;\n",
+"K=1.38*10^-23;          //in J/K\n",
+"l=1;            //in km\n",
+"L1=630;         //in nm\n",
+"L2=1330;         //in nm\n",
+"L3=1550;         //in nm\n",
+"disp('Rayleight scattering coefficient');\n",
+"Y1=8*%pi^3*n^8*p^2*B*K*Tf/3/(L1*10^-9)^4;\n",
+"Y2=8*%pi^3*n^8*p^2*B*K*Tf/3/(L2*10^-9)^4;\n",
+"Y3=8*%pi^3*n^8*p^2*B*K*Tf/3/(L3*10^-9)^4;  \n",
+"mprintf(' for L1= 630nm, is %e',Y1);\n",
+"mprintf('\n for L2= 1330nm, is %e',Y2);\n",
+"mprintf('\n for L3= 1550nm, is %e',Y3);\n",
+"//Misprinted answer\n",
+"\n",
+"disp('Rayleight scattering attenuation factor');\n",
+"Fr1=%e^-(Y1*l*10^3);\n",
+"Fr2=%e^-(Y2*l*10^3);\n",
+"Fr3=%e^-(Y3*l*10^3);\n",
+"printf(' \n for Y1=  0.00179 is %0.2f',Fr1);\n",
+"printf(' \n for Y2=  0.00009 is %0.2f',Fr2);\n",
+"printf(' \n for Y3=  0.0000182 is %0.2f\n',Fr3);\n",
+"//\n",
+"\n",
+"disp('Rayleight scattering attenuation ');\n",
+"Ar1=10*log10(Fr1^-1);\n",
+"Ar2=10*log10(Fr2^-1);\n",
+"Ar3=10*log10(Fr3^-1);\n",
+"printf(' \n for Ar1=  0.17 is %0.2f dB/km',Ar1);\n",
+"printf(' \n for Ar2=  0.91 is %0.2f dB/km',Ar2);\n",
+"printf(' \n for Ar3=  0.98 is %0.3f dB/km',Ar3);\n",
+"//For L3 answers in book are misprinted\n",
+"//Rounding off errors in answer"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.5: SBS_threshold_optical_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 9\n",
+"//page no 304\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=850;          //in nm\n",
+"L1=0.850;           //converted L in micrometer for using in given formula\n",
+"A=0.5;          //in dB/km\n",
+"d=5;        //in micrometer\n",
+"Bw=1;           //in Gz\n",
+"Po=4.4*10^-3*A*Bw*L1^2*d^2;\n",
+"printf(' \n Po(Th) =  %0.3f W',Po);\n",
+"printf(' \n Therefore,Po(Th) =  %0.0f mW',Po*1000);\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.6: SBS_threshold_optical_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 9\n",
+"//page no 304\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=1330;          //in nm\n",
+"L1=1.330;           //converted L in micrometer for using in given formula\n",
+"A=0.5;          //in dB/km\n",
+"d=5;        //in micrometer\n",
+"Bw=1;           //in Gz\n",
+"Po=4.4*10^-3*A*Bw*L1^2*d^2;\n",
+"printf(' \n Po(Th) =  %0.3f W',Po);\n",
+"printf(' \n Therefore,Po(Th) =  %0.0f mW',Po*1000);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.7: SBS_threshold_optical_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 9\n",
+"//page no 304\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=1550;          //in nm\n",
+"L1=1.550;           //converted L in micrometer for using in given formula\n",
+"A=0.5;          //in dB/km\n",
+"d=5;        //in micrometer\n",
+"Bw=1;           //in Gz\n",
+"Po=4.4*10^-3*A*Bw*L1^2*d^2;\n",
+"printf(' \n Po(Th) =  %0.3f W',Po);\n",
+"printf(' \n Therefore,Po(Th) =  %0.0f mW',Po*1000);"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.8: SBS_threshold_optical_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 9\n",
+"//page no 304\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=850;          //in nm\n",
+"L1=0.850;           //converted L in micrometer for using in given formula\n",
+"A=0.5;          //in dB/km\n",
+"d=8;        //in micrometer\n",
+"Bw=1;           //in Gz\n",
+"Po=4.4*10^-3*A*Bw*L1^2*d^2;\n",
+"printf(' \n Po(Th) =  %0.3f W',Po);\n",
+"printf(' \n Therefore,Po(Th) =  %0.0f mW',Po*1000);//answer is slightly different due to rounding off"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 9.9: SBS_threshold_optical_power.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"\n",
+"\n",
+"\n",
+"\n",
+"\n",
+"//Chapter 9\n",
+"//page no 304\n",
+"//given\n",
+"clc;\n",
+"clear all;\n",
+"L=850;          //in nm\n",
+"L1=0.850;           //converted L in micrometer for using in given formula\n",
+"A=0.5;          //in dB/km\n",
+"d=10;        //in micrometer\n",
+"Bw=1;           //in Gz\n",
+"Po=4.4*10^-3*A*Bw*L1^2*d^2;\n",
+"printf(' \n Po(Th) =  %0.3f W',Po);\n",
+"printf(' \n Therefore,Po(Th) =  %0.0f mW',Po*1000);"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}