initial commit / add all books

129 files changed, 1690 insertions, 0 deletions

diff --git a/2183/CH2/EX2.1/EX_2_1.sce b/2183/CH2/EX2.1/EX_2_1.sce
new file mode 100755
index 000000000..461427caa
--- /dev/null
+++ b/2183/CH2/EX2.1/EX_2_1.sce
@@ -0,0 +1,9 @@
+// Example 2.1:Critical angle

+clc;

+clear;

+close;

+n2=1.402;//Waveguide Refractive Index

+n1=1.495;//Cladding Refractive Index

+no=1;// for air

+Oc=asind(n2/n1);// Critical Angle

+disp(Oc,"Critical angle in degree")

diff --git a/2183/CH2/EX2.10/EX_2_10.sce b/2183/CH2/EX2.10/EX_2_10.sce
new file mode 100755
index 000000000..b941829c4
--- /dev/null
+++ b/2183/CH2/EX2.10/EX_2_10.sce
@@ -0,0 +1,12 @@
+// Example 2.10:Number of modes
+clc;
+clear;
+close;
+NA=0.2
+a=40;// core radius in micro meters
+h=1;//wavelngth in micro meters
+v=(2*%pi*(a/2)*NA)/h;//Normalised wavelngth
+m= round (v^2/4);// number of modes
+disp(m,"number of modes")
+
+
diff --git a/2183/CH2/EX2.11/EX_2_11.sce b/2183/CH2/EX2.11/EX_2_11.sce
new file mode 100755
index 000000000..a34eba2a2
--- /dev/null
+++ b/2183/CH2/EX2.11/EX_2_11.sce
@@ -0,0 +1,16 @@
+// Example 2.11:diameter
+clc;
+clear;
+close;
+v1=1.2;//
+v2=2.4;//
+h=0.85;//in micro meter
+n1=1.5;//refrative index
+d1=0.015;//
+a1=((v1*h)/(2*%pi*n1*sqrt(2*d1)));//in micro meter
+d2=0.0015;//
+a2=((v2*h)/(2*%pi*n1*sqrt(2*d2)));//in micro meter
+disp(2*a1,"diameter (case 1) in micro meters is")
+disp(2*a2,"diameter (case 2) in micro meters is")
+//answer is wrong in the textbook
+
diff --git a/2183/CH2/EX2.12/EX_2_12.sce b/2183/CH2/EX2.12/EX_2_12.sce
new file mode 100755
index 000000000..3484b0f02
--- /dev/null
+++ b/2183/CH2/EX2.12/EX_2_12.sce
@@ -0,0 +1,13 @@
+// Example 2.12:diameter
+clc;
+clear;
+close;
+v=2.4*sqrt(2);//
+h=1.3;//in micro meter
+n1=1.5;//refrative index
+d1=0.01;//
+a1=((v*h)/(2*%pi*n1*sqrt(2*d1)));//in micro meter
+disp(a1,"radius in micro meters is")
+
+
+
diff --git a/2183/CH2/EX2.13/EX_2_13.sce b/2183/CH2/EX2.13/EX_2_13.sce
new file mode 100755
index 000000000..130a3b3f9
--- /dev/null
+++ b/2183/CH2/EX2.13/EX_2_13.sce
@@ -0,0 +1,10 @@
+// Example 2.13:Cutoff Wavelength

+clc;

+clear;

+close;

+n1=1.48;//Waveguide Refractive Index

+a=4.8;// core radius in micro meters

+d= 0.0025;// Cange in core-cladding refractive index

+Hc= (2*%pi*a*sqrt(2*d)*n1)/2.4;

+disp(round(Hc*10^3),"Cutoff wavelength in nano meters")

+//answer is wrong in the textbook

diff --git a/2183/CH2/EX2.15/EX_2_15.sce b/2183/CH2/EX2.15/EX_2_15.sce
new file mode 100755
index 000000000..0e3b8a396
--- /dev/null
+++ b/2183/CH2/EX2.15/EX_2_15.sce
@@ -0,0 +1,10 @@
+// Example 2.15:diameter
+clc;
+clear;
+close;
+mfd=11.6;//in micro meter
+a=mfd/2;//in micro meters
+v=2.2;//
+alpha=((a*10^-6)/(0.65+1.619*sqrt(v)+2.879*((v)^-6)));//
+disp(2*alpha*10^6,"core diameter in micro meter ")
+//answer is wrong in the textbook
diff --git a/2183/CH2/EX2.16/EX_2_16.sce b/2183/CH2/EX2.16/EX_2_16.sce
new file mode 100755
index 000000000..828b5e522
--- /dev/null
+++ b/2183/CH2/EX2.16/EX_2_16.sce
@@ -0,0 +1,12 @@
+// Example 2.16:ESI relative refractive index
+clc;
+clear;
+close;
+h=1.190;//micro meter
+sp=5.2;//in micro meter
+n=1.5;//refractive index
+alpha2=1.820*sp;//in micro meter
+desi1=(0.293/(n)^2);//
+desi2=desi1*(1.19/alpha2)^2;//
+disp(desi2*100,"ESI relative refrative index difference in percentage is")
+//answer is wrong in the textbook
diff --git a/2183/CH2/EX2.2.a/EX_2_2_a.sce b/2183/CH2/EX2.2.a/EX_2_2_a.sce
new file mode 100755
index 000000000..881a64b74
--- /dev/null
+++ b/2183/CH2/EX2.2.a/EX_2_2_a.sce
@@ -0,0 +1,11 @@
+// Example 2.2.a: Critical Angle

+clc;

+clear;

+close;

+n1=1.50;//Waveguide Refractive Index

+n2=1.47;//Cladding Refractive Index

+Oc=asind(n2/n1);//Critical Angle

+oc=floor(Oc);//

+x=Oc-oc;//

+disp("CRITICAL ANGLE IS "+string(oc)+" DEGREE AND "+string(round((60*(x))))+" MINUTES ")

+//answer is wrong in the textbook

diff --git a/2183/CH2/EX2.2.b/EX_2_2_b.sce b/2183/CH2/EX2.2.b/EX_2_2_b.sce
new file mode 100755
index 000000000..9ae2e8bbb
--- /dev/null
+++ b/2183/CH2/EX2.2.b/EX_2_2_b.sce
@@ -0,0 +1,8 @@
+// Example 2.2.b:Numerical Aperture

+clc;

+clear;

+close;

+n1=1.50;//Waveguide Refractive Index

+n2=1.47;//Cladding Refractive Index

+NA=sqrt(n1^2-n2^2);// Numerical Aperture

+disp(NA,"Numerical Aperture is")

diff --git a/2183/CH2/EX2.2.c/EX_2_2_c.sce b/2183/CH2/EX2.2.c/EX_2_2_c.sce
new file mode 100755
index 000000000..dc05dfe4c
--- /dev/null
+++ b/2183/CH2/EX2.2.c/EX_2_2_c.sce
@@ -0,0 +1,13 @@
+// Example 2.2.c: Acceptance Angle

+clc;

+clear;

+close;

+n1=1.50;//Waveguide Refractive Index

+n2=1.47;//Cladding Refractive Index

+h= 1.3;// Wavelenght in micrometers

+NA=sqrt(n1^2-n2^2);// Numerical Aperture

+Oa=asind(NA);//ACCEPTANCE ANGLE

+oa=floor(Oa);//

+x=Oa-oa;//

+disp("ACCEPTANCE ANGLE IS "+string(oa)+" DEGREE AND "+string(round((60*(x))))+" MINUTES ")

+//answer is wrong in the textbook

diff --git a/2183/CH2/EX2.3/EX_2_3.sce b/2183/CH2/EX2.3/EX_2_3.sce
new file mode 100755
index 000000000..dbd35ac10
--- /dev/null
+++ b/2183/CH2/EX2.3/EX_2_3.sce
@@ -0,0 +1,17 @@
+// Example 2.3:Numerical Aperture ,Acceptance Angle and criticle angke

+clc; 

+clear;

+close;

+n1=1.46;//core Refractive Index

+d=1;// refractive index differnce in percentage

+NA=n1*(sqrt(2*(d/100)));// Numerical Aperture

+Sa= %pi*(NA)^2;//solid accepance angle in strad

+r=1-(d/100);//ratio of refractive index

+Oc=asind(r);//criticle angle in degree

+oc=floor(Oc);//

+x=Oc-oc;//

+disp(NA,"numerical aperture is")

+disp(Sa,"solid acceptance angle in air in stard is")

+disp("CRITICAL ANGLE IS "+string(oc)+" DEGREE AND "+string(round((60*(x))))+" MINUTES ")

+

+

diff --git a/2183/CH2/EX2.4/EX_2_4.sce b/2183/CH2/EX2.4/EX_2_4.sce
new file mode 100755
index 000000000..b32c4c2b6
--- /dev/null
+++ b/2183/CH2/EX2.4/EX_2_4.sce
@@ -0,0 +1,8 @@
+// Example 2.4;Critical Angle

+clc;

+clear;

+close;

+n1=1.48;//Waveguide Refractive Index

+n2=1.46;//Cladding Refractive Index

+Oc=asind(sqrt((1-(n2/n1)^2)));//Critical Angle

+disp(Oc,"critical angle in degree is")

diff --git a/2183/CH2/EX2.5/EX_2_5.sce b/2183/CH2/EX2.5/EX_2_5.sce
new file mode 100755
index 000000000..cb7e6c5e2
--- /dev/null
+++ b/2183/CH2/EX2.5/EX_2_5.sce
@@ -0,0 +1,11 @@
+// Example 2.5: Core and Cladding Index

+clc;

+clear;

+close;

+NA=0.3;// numerical aperture

+d= 0.01;// Cange in core-cladding refractive index

+r=(1-d);//ratio

+n1=sqrt(((NA)^2)/(1-r^2));//core refrative index

+n2= n1-(d*n1);

+disp(n1,"refrative index of core is")

+disp(n2,"Refradctive index of cladding is")

diff --git a/2183/CH2/EX2.6/EX_2_6.sce b/2183/CH2/EX2.6/EX_2_6.sce
new file mode 100755
index 000000000..56f57bb8b
--- /dev/null
+++ b/2183/CH2/EX2.6/EX_2_6.sce
@@ -0,0 +1,16 @@
+// Example 2.6: compare acceptance angle
+clc;
+clear;
+close;
+NA=0.4;// numerical aperture
+r2=100;//angle at which rays change dirction
+r=r2/2;//in degree
+Oa=asind(NA);//ACCEPTANCE ANGLE
+oa=floor(Oa);//
+x=Oa-oa;//
+Oas=asind(NA/cosd(r));//ACCEPTANCE ANGLE for skew rays in degree
+oas=floor(Oas);//
+xs=Oas-oas;//
+disp("ACCEPTANCE ANGLE IS "+string(oa)+" DEGREE AND "+string(round((60*(x))))+" MINUTES ")
+disp("ACCEPTANCE ANGLE FOR MEIDONAL RAYS IS "+string(oas)+" DEGREE AND "+string(round((60*(xs))))+" MINUTES ")
+
diff --git a/2183/CH2/EX2.7/EX_2_7.sce b/2183/CH2/EX2.7/EX_2_7.sce
new file mode 100755
index 000000000..bb63d7050
--- /dev/null
+++ b/2183/CH2/EX2.7/EX_2_7.sce
@@ -0,0 +1,10 @@
+// Example 2.7:Number of the modes

+clc;

+clear;

+close;

+a=50;;// Radius in meter

+NA=0.29;// Numerical Aperture

+h=0.85;// Wavelength in meter

+M=round((2*%pi^2*a^2*NA^2)/(h)^2);//

+disp(M,"Number of modes")

+//answer is wrong in the textbook

diff --git a/2183/CH2/EX2.8/EX_2_8.sce b/2183/CH2/EX2.8/EX_2_8.sce
new file mode 100755
index 000000000..a78cc1d4f
--- /dev/null
+++ b/2183/CH2/EX2.8/EX_2_8.sce
@@ -0,0 +1,13 @@
+// Example 2.8:Number of modes

+clc;

+clear;

+close;

+n1=1.5;//Waveguide Refractive Index

+d= 0.015;// Cange in core-cladding refractive index

+a=40;// core radius in micro meters

+h=0.85;//wavelngth in micro meters

+v=(2*%pi*a*n1*sqrt(2*d))/h;//Normalised wavelngth

+m= round (v^2/2);// number of modes

+disp(m,"number of modes")

+//answer is wrong in the textbook

+

diff --git a/2183/CH2/EX2.9/EX_2_9.sce b/2183/CH2/EX2.9/EX_2_9.sce
new file mode 100755
index 000000000..cc566bd6f
--- /dev/null
+++ b/2183/CH2/EX2.9/EX_2_9.sce
@@ -0,0 +1,11 @@
+// Example 2.9:Maximum Core Readius

+clc;

+clear;

+close;

+n1=1.55;//Waveguide Refractive Index

+n2=1.52;//

+d= n1-n2;// Cange in core-cladding refractive index

+h=1550;//wavelngth in nano meters

+a=((2.405*h*10^-9)/(2*%pi*sqrt(n1^2-n2^2)));//Core Radius

+disp(a*10^6,"maximum core radius in micro meters")

+

diff --git a/2183/CH3/EX3.1.a/Ex_3_1_a.sce b/2183/CH3/EX3.1.a/Ex_3_1_a.sce
new file mode 100755
index 000000000..c97434939
--- /dev/null
+++ b/2183/CH3/EX3.1.a/Ex_3_1_a.sce
@@ -0,0 +1,13 @@
+// Example 3.1.a:fracture stress
+clc;
+clear;
+close;
+la=0.16;//bond length in nm
+st=2.6*10^6;//psi
+psi=6894.76;//Nm^-2
+e=9*10^10;//NM^-2
+yp=((4*la*10^-9*(st*psi)^2)/(e));//in joules
+c=10^-8;//
+sf=sqrt((2*e*yp)/(%pi*c));//N/m^2
+sf1=sf/(psi);//psi
+disp(sf1,"fracture stress in psi is")
diff --git a/2183/CH3/EX3.1.b/Ex_3_1_b.sce b/2183/CH3/EX3.1.b/Ex_3_1_b.sce
new file mode 100755
index 000000000..ce3a50ef1
--- /dev/null
+++ b/2183/CH3/EX3.1.b/Ex_3_1_b.sce
@@ -0,0 +1,14 @@
+// Example 3.1.b:percentage strain
+clc;
+clear;
+close;
+la=0.16;//bond length in nm
+st=2.6*10^6;//psi
+psi=6894.76;//Nm^-2
+e=9*10^10;//NM^-2
+yp=((4*la*10^-9*(st*psi)^2)/(e));//in joules
+c=10^-8;//
+sf=sqrt((2*e*yp)/(%pi*c));//N/m^2
+sf1=sf/(psi);//psi
+e=(sf/e)*100;//
+disp(round(e),"percentage strain (%) is")
diff --git a/2183/CH3/EX3.2/Ex_3_2.sce b/2183/CH3/EX3.2/Ex_3_2.sce
new file mode 100755
index 000000000..04f4c395b
--- /dev/null
+++ b/2183/CH3/EX3.2/Ex_3_2.sce
@@ -0,0 +1,13 @@
+//Example 3.2 // The loss
+clc;
+clear;
+close;
+//given data :
+format('v',5)
+n1=1.5;
+n2=1;
+r=((n1-n2)/(n1+n2))^2;
+L_f= (-10*log10(1-r));
+disp(L_f,"The optical loss at one end,(dB) = ")
+Lt=2*L_f;
+disp(Lt,"Total loss at both joints,(dB) = ")
diff --git a/2183/CH3/EX3.3.a/Ex_3_3_a.sce b/2183/CH3/EX3.3.a/Ex_3_3_a.sce
new file mode 100755
index 000000000..de47f9c92
--- /dev/null
+++ b/2183/CH3/EX3.3.a/Ex_3_3_a.sce
@@ -0,0 +1,11 @@
+// Example 3.3.a:insertion loss
+clc;
+clear;
+close;
+n12=1.5;//refractive index
+y=5;//lateral misalignment in micro meter
+a2=50;//dia in micro meter
+nlat=((16*n12^2)/(%pi*(1+n12)^4))*((2*acos(y/a2))-(y/a2)*sqrt(1-(y/a2)^2));//
+loss=-10*log10(nlat);//loss in dB
+disp(loss,"insertion loss in dB is")
+//answer is wrong in the textbook
diff --git a/2183/CH3/EX3.3.b/ex_3_3_b.sce b/2183/CH3/EX3.3.b/ex_3_3_b.sce
new file mode 100755
index 000000000..36a2e0e6d
--- /dev/null
+++ b/2183/CH3/EX3.3.b/ex_3_3_b.sce
@@ -0,0 +1,11 @@
+// Example 3.3.b:insertion loss
+clc;
+clear;
+close;
+n12=1.5;//refractive index
+y=5;//lateral misalignment in micro meter
+a2=50;//dia in micro meter
+nlat=(1/(%pi))*((2*acos(y/a2))-(y/a2)*sqrt(1-(y/a2)^2));//
+loss=-10*log10(nlat);//loss in dB
+disp(loss,"insertion loss in dB is")
+//answer is wrong in the textbook
diff --git a/2183/CH3/EX3.4.a/Ex_3_4_a.sce b/2183/CH3/EX3.4.a/Ex_3_4_a.sce
new file mode 100755
index 000000000..bda68476d
--- /dev/null
+++ b/2183/CH3/EX3.4.a/Ex_3_4_a.sce
@@ -0,0 +1,13 @@
+//Example 3.4.a // insertion loss
+clc;
+clear;
+close;
+//given data :
+y=3;// in micro-m
+alfa=2;
+d=50;// in micro-m
+a=d/alfa;
+Lt=0.85*(y/a);
+eta_lat=1-Lt;
+L_lat=-10*log10(eta_lat);
+disp(L_lat,"The insertion loss,(dB) = ")
diff --git a/2183/CH3/EX3.4.b/Ex_3_4_b.sce b/2183/CH3/EX3.4.b/Ex_3_4_b.sce
new file mode 100755
index 000000000..a509effb5
--- /dev/null
+++ b/2183/CH3/EX3.4.b/Ex_3_4_b.sce
@@ -0,0 +1,13 @@
+//Example 3.4.b // insertion loss
+clc;
+clear;
+close;
+//given data :
+y=3;// in micro-m
+alfa=2;
+d=50;// in micro-m
+a=d/alfa;
+Lt=0.75*(y/a);
+eta_lat=1-Lt;
+L_lat=-10*log10(eta_lat);
+disp(L_lat,"The insertion loss,(dB) = ")
diff --git a/2183/CH3/EX3.5/Ex_3_5.sce b/2183/CH3/EX3.5/Ex_3_5.sce
new file mode 100755
index 000000000..42a211909
--- /dev/null
+++ b/2183/CH3/EX3.5/Ex_3_5.sce
@@ -0,0 +1,15 @@
+//Example 3.5 // insertion loss
+clc;
+clear;
+close;
+//given data :
+n1BYn2=1.48;
+NA1=0.2;
+n2theta=(5*%pi)/180;
+NA2=0.4;
+eta1=((16*(n1BYn2)^2)/(1+n1BYn2)^4)*(1-((n2theta/(%pi*NA1))));
+L_ang1=-10*log10(eta1);
+eta2=((16*(n1BYn2)^2)/(1+n1BYn2)^4)*(1-((n2theta/(%pi*NA2))));
+L_ang2=-10*log10(eta2)
+disp(L_ang1,"the insertion loss,(dB) = ")
+disp(L_ang2,"the insertion loss,(dB) = ")
diff --git a/2183/CH3/EX3.6/Ex_3_6.sce b/2183/CH3/EX3.6/Ex_3_6.sce
new file mode 100755
index 000000000..f5df20865
--- /dev/null
+++ b/2183/CH3/EX3.6/Ex_3_6.sce
@@ -0,0 +1,16 @@
+//Example 3.6 //total insertion loss
+clc;
+clear;
+close;
+//given data :
+a=8/2;// in micro-m
+V=2.4;
+w=a*((0.65+(1.62*V^(-3/2))+(2.88*V^-6))/sqrt(2));
+y=1;
+NA=0.1;
+theta=%pi/180;
+n1=1.46;
+T_lat=2.17*(y/w)^2;
+T_ang=2.17*((theta*w*n1*V)/(a*NA))^2;
+T=T_lat+T_ang;
+disp(T,"Total insertion loss,(dB) = ")
diff --git a/2183/CH3/EX3.7/Ex_3_7.sce b/2183/CH3/EX3.7/Ex_3_7.sce
new file mode 100755
index 000000000..b89713015
--- /dev/null
+++ b/2183/CH3/EX3.7/Ex_3_7.sce
@@ -0,0 +1,12 @@
+//Example 3.7 //The loss
+clc;
+clear;
+close;
+//given data :
+a=9.2;// in micro-m
+b=8.4;// in micro-m
+wo2=b/2;
+wo1=a/2;
+L=-10*log10(4*((wo2/wo1)+(wo1/wo2))^-2);
+disp(L,"The loss,L(dB) = ")
+// answer is wrong in textbook  
diff --git a/2183/CH3/EX3.8/Ex_3_8.sce b/2183/CH3/EX3.8/Ex_3_8.sce
new file mode 100755
index 000000000..aa1f8709c
--- /dev/null
+++ b/2183/CH3/EX3.8/Ex_3_8.sce
@@ -0,0 +1,19 @@
+//Example 3.8.a // Excess loss
+clc;
+clear;
+close;
+//given data :
+P1=60;// in micro-W
+P3=26;// in micro-W
+P4=27.5;// in micro-W
+P2=0.004;// in micro-W
+E_loss=10*log10((P1/(P3+P4)));
+disp(E_loss,"(a). The excess loss,(dB) = ")
+I_loss=10*log10(P1/P4);
+disp(I_loss,"(b).i. insertion loss port 1 to port 4,(dB) = ")
+I_loss1=10*log10(P1/P3);
+disp(I_loss1,"(b).ii. insertion loss port 1 to port 3,(dB) = ")
+C_talk=10*log10(P2/P1);
+disp(C_talk,"Cross talk,(db) = ")
+sr=(P3/(P3+P4))*100;
+disp(sr,"Split ratio,(%) = ")
diff --git a/2183/CH3/EX3.9/Ex_3_9.sce b/2183/CH3/EX3.9/Ex_3_9.sce
new file mode 100755
index 000000000..b8b06f3f1
--- /dev/null
+++ b/2183/CH3/EX3.9/Ex_3_9.sce
@@ -0,0 +1,15 @@
+//Example 3.9 // Total loss and Average insertion loss
+clc;
+clear;
+close;
+//given data :
+N=32;
+Pin=10^3;
+a=14;// in micro-W
+pf=a*N;
+s_loss=10*log10(N);
+e_loss=10*log10(Pin/pf);
+T_loss=s_loss+e_loss;
+disp(T_loss,"Total loss,(dB) = ")
+I_loss=10*log10(Pin/a);
+disp(I_loss,"The insertion loss,(dB) = " )
diff --git a/2183/CH4/EX4.1.a/Ex_4_1_a.sce b/2183/CH4/EX4.1.a/Ex_4_1_a.sce
new file mode 100755
index 000000000..b3bfe3ad4
--- /dev/null
+++ b/2183/CH4/EX4.1.a/Ex_4_1_a.sce
@@ -0,0 +1,9 @@
+// Example 4.1.a:signal attenuation

+clc;

+clear;

+close;

+L=8;// Length of fiber in km

+Pi=120*10^-6;// input power in Watt

+Po=4*10^-6;//Output power in Watt

+alpha=(10*(log10(Pi/Po)));//Loss in dB

+disp(alpha,"signal attenuation in dB")

diff --git a/2183/CH4/EX4.1.b/Ex_4_1_b.sce b/2183/CH4/EX4.1.b/Ex_4_1_b.sce
new file mode 100755
index 000000000..674377df3
--- /dev/null
+++ b/2183/CH4/EX4.1.b/Ex_4_1_b.sce
@@ -0,0 +1,10 @@
+// Example 4.1.b:signal attenuation per km
+clc;
+clear;
+close;
+L=8;// Length of fiber in km
+Pi=120*10^-6;// input power in Watt
+Po=4*10^-6;//Output power in Watt
+alpha=(10*(log10(Pi/Po)));//Loss in dB
+alphal=alpha/L
+disp(alphal,"signal attenuation per km in dB/km is")
diff --git a/2183/CH4/EX4.1.c/Ex_4_1_c.sce b/2183/CH4/EX4.1.c/Ex_4_1_c.sce
new file mode 100755
index 000000000..deec11704
--- /dev/null
+++ b/2183/CH4/EX4.1.c/Ex_4_1_c.sce
@@ -0,0 +1,13 @@
+// Example 4.2.c:Loss for 10Km

+clc;

+clear;

+close;

+L=8;// Length of fiber in km

+Pi=120*10^-6;// input power in Watt

+Po=4*10^-6;//Output power in Watt

+alpha= round(10*(log10(Pi/Po)));//Loss in dB

+alphadb= alpha/L;//Loss in dB/Km

+alphadb2=alphadb*10;// Loss along 10Km fiber length in dB

+Ds=alphadb2+9;// Due to splices at 1km Interval

+disp(Ds,"Atenuation Due to splices at 1km Interval in dB")

+

diff --git a/2183/CH4/EX4.1.d/Ex_4_1_d.sce b/2183/CH4/EX4.1.d/Ex_4_1_d.sce
new file mode 100755
index 000000000..4414a5ef3
--- /dev/null
+++ b/2183/CH4/EX4.1.d/Ex_4_1_d.sce
@@ -0,0 +1,15 @@
+// Example 4.1.d:Ratio of powers

+clc;

+clear;

+close;

+L=8;// Length of fiber in km

+Pi=120*10^-6;// input power in Watt

+Po=4*10^-6;//Output power in Watt

+alpha= round(10*(log10(Pi/Po)));//Loss in dB

+alphadb= alpha/L;//Loss in dB/Km

+alphadb2=alphadb*10;// Loss along 10Km fiber length in dB

+Ds=alphadb2+9;// Due to splices at 1km Interval

+rt= 10^(Ds/10);// Ratio of input to output power

+disp(rt,"Ratio of input to output power")

+//answer is wrong in the textbook

+

diff --git a/2183/CH4/EX4.10.a/Ex_4_10_a.sce b/2183/CH4/EX4.10.a/Ex_4_10_a.sce
new file mode 100755
index 000000000..e8ae9e812
--- /dev/null
+++ b/2183/CH4/EX4.10.a/Ex_4_10_a.sce
@@ -0,0 +1,14 @@
+// Example 4.10.a;//TOTAL RMS Pulse broadning 

+clc;

+clear;

+close;

+M=250;//dispersion parametr picosecond per nano meter per kilometer

+Sa=50;//spectral width in nm

+NA=0.3;//numerical aperture

+n1=1.45;// Core refractibve index

+C=2.998*10^8;//Speed of light in m/s

+L=1;//length in Km

+Sm=M*L*Sa*10^-3;//rms pulse broadning due to material dispersion

+Ss=(L*10^3*NA^2)/(4*sqrt(3)*C*n1)*10^9;//Pulse broadning due to intermodal dispersion in ns/km

+St=sqrt(Sm^2+Ss^2);// Total broadning

+disp(St,"Total broadning ns per km is")

diff --git a/2183/CH4/EX4.10.b/Ex_4_10_b.sce b/2183/CH4/EX4.10.b/Ex_4_10_b.sce
new file mode 100755
index 000000000..80c694f88
--- /dev/null
+++ b/2183/CH4/EX4.10.b/Ex_4_10_b.sce
@@ -0,0 +1,15 @@
+// Example 4.10.b;//bandwidth length product

+clc;

+clear;

+close;

+M=250;//dispersion parameter picosecond per nano meter per kilometer

+Sa=50;//spectral width in nm

+NA=0.3;//numerical aperture

+n1=1.45;// Core refractibve index

+C=2.998*10^8;//Speed of light in m/s

+L=1;//length in km

+Sm=M*L*Sa*10^-3;//rms pulse broadning due to material dispersion

+Ss=(L*10^3*NA^2)/(4*sqrt(3)*C*n1)*10^9;//Pulse broadning due to intermodal dispersion in ns/km

+St=sqrt(Sm^2+Ss^2);// Total broadning

+BL= (0.2/(St*10^-9))*10^-6;// Bandwidth length product in Mega hertz km

+disp(BL,"Bandwidth length product is,(MHz-km)")

diff --git a/2183/CH4/EX4.11/Ex_4_11.sce b/2183/CH4/EX4.11/Ex_4_11.sce
new file mode 100755
index 000000000..3f08720e8
--- /dev/null
+++ b/2183/CH4/EX4.11/Ex_4_11.sce
@@ -0,0 +1,14 @@
+// Example 4.11 //compare the total first order dispersion
+clc;
+clear;
+close;
+so=0.095;//ps nm^-2 km^-1
+h=1270;//in nm
+ho=1320;//in nm
+dt1=((h*so)/4)*((1-(ho/h)^4));// in ps nm^-1 km^-1
+h1=1520;//in nm
+dt21=((h1*so)/4)*((1-(ho/h1)^4));// in ps nm^-1 km^-1
+dt2=dt21-(13.5+4.1);// in ps nm^-1 km^-1
+disp(dt1,"first order dispersion at wavelength 1270nm in ps nm^-1 km^-1")
+disp(dt2,"first order dispersion at wavelength 1320nm in ps nm^-1 km^-1")
+//answer is wrong in the textbook
diff --git a/2183/CH4/EX4.12/Ex_4_12.sce b/2183/CH4/EX4.12/Ex_4_12.sce
new file mode 100755
index 000000000..5fba454e2
--- /dev/null
+++ b/2183/CH4/EX4.12/Ex_4_12.sce
@@ -0,0 +1,12 @@
+// Example 4.12;//bit rate
+clc;
+clear;
+close;
+dx=2;//in ps/nm-km
+L=100;//in km
+h1=1310;// in nm
+h2=1300;//in nm
+dh=h1-h2;//in nm
+brl=(1/(4*dx*(dh/10)));//in Gbps-km
+br=brl/L;//in Gbps
+disp(br*10^3,"bit rate in Gbps")
diff --git a/2183/CH4/EX4.13/Ex_4_13.sce b/2183/CH4/EX4.13/Ex_4_13.sce
new file mode 100755
index 000000000..de58ecb36
--- /dev/null
+++ b/2183/CH4/EX4.13/Ex_4_13.sce
@@ -0,0 +1,9 @@
+// Example 4.13;//Maximum bit rate

+clc;

+clear;

+close;

+L=20;//Length in km

+Dt2=300*10^-12;//Birefringent in second per kilometer

+B=(0.9)/(Dt2*L*10^3);//

+Btm= round((B/0.55)*10^-3);// maximum bit rate in kilo bit per second

+disp(Btm,"maximum bit rate in kilo bit per second")

diff --git a/2183/CH4/EX4.14/Ex_4_14.sce b/2183/CH4/EX4.14/Ex_4_14.sce
new file mode 100755
index 000000000..4064d4389
--- /dev/null
+++ b/2183/CH4/EX4.14/Ex_4_14.sce
@@ -0,0 +1,11 @@
+// Example 4.14 //birefringence

+clc;

+clear;

+close;

+Lbc1=0.7;//beat length micro meter

+h=1.3;//wavelength in micro meter

+Bf1=((h*10^-6)/(Lbc1*10^-3));// birefringence when beat length = 0.5mm

+Lbc2=80;//beat length meter

+Bf2=((h*10^-6)/(Lbc2));// birefringence when beat length = 60 meter

+disp(Bf1,"birefringence (high birefringent fiber) when beat length = 0.7micro meter")

+disp(Bf2,"birefringence (lower birefringent fiber) when beat length = 80 meter")

diff --git a/2183/CH4/EX4.15/Ex_4_15.sce b/2183/CH4/EX4.15/Ex_4_15.sce
new file mode 100755
index 000000000..91fe943d4
--- /dev/null
+++ b/2183/CH4/EX4.15/Ex_4_15.sce
@@ -0,0 +1,12 @@
+// Example 4.15//Bifringence and differnce between the propogation constt.

+clc;

+clear;

+close;

+Lb=0.09;//Birefringent Coherence over length in meter

+h=0.9;//wavelength in micro meter

+df=1;//spectral width in nano meter

+Bf=((h*10^-6)/(Lb));//modal bifringence 

+Lbc= (((h*10^-6)^2)/(Bf*df*10^-9));//Coherance length in meter

+Bxy=(2*%pi)/(Lb);//Diff in the propogation constant

+disp(Bf,"modal bifringence  is")

+disp(Bxy,"Difference in the propgation constants. is")

diff --git a/2183/CH4/EX4.16/Ex_4_16.sce b/2183/CH4/EX4.16/Ex_4_16.sce
new file mode 100755
index 000000000..b502e4376
--- /dev/null
+++ b/2183/CH4/EX4.16/Ex_4_16.sce
@@ -0,0 +1,8 @@
+// Example 4.16//bit rate
+clc;
+clear;
+close;
+pmc=0.5;//ps/sqrt(km)
+l=100;//km
+br=(1/(4*pmc*sqrt(l)));//
+disp(br*10^3,"bit rate is ,(Gbps)=")
diff --git a/2183/CH4/EX4.2/Ex_4_2.sce b/2183/CH4/EX4.2/Ex_4_2.sce
new file mode 100755
index 000000000..78e1f0b9a
--- /dev/null
+++ b/2183/CH4/EX4.2/Ex_4_2.sce
@@ -0,0 +1,30 @@
+// Example 4.2:Attenuation 

+clc;

+clear;

+close;

+L=1;//in km

+h1=0.63;//in micro meter

+h2=1;//in micro meter

+h3=1.3;//in micro meter

+Tf=1400;//Temperature in Kelvin

+p=0.286;//photoelastic coefficient of silica

+n=1.46;//Refractive index of silica

+Bc=7*10^-11;//isothermal compersebility in in Metere square per N

+K=1.38*10^-23;// boltzman constt. in julian per Kelvin

+x1= (h1*10^-6);

+x2= (h2*10^-6);

+x3= (h3*10^-6);

+Yr1=(8*%pi^3*n^8*p^2*Bc*K*Tf)/(3*(x1)^4);//ray leigh scattering coefficient

+Ekm1= exp(-Yr1*L*10^3)

+alpha1=10*(log10(1/Ekm1));//Attenuation in dB/km

+Yr2=(8*%pi^3*n^8*p^2*Bc*K*Tf)/(3*(x2)^4);//ray leigh scattering coefficient

+Ekm2= exp(-Yr2*L*10^3)

+alpha2=10*(log10(1/Ekm2));//Attenuation in dB/km

+Yr3=(8*%pi^3*n^8*p^2*Bc*K*Tf)/(3*(x3)^4);//ray leigh scattering coefficient

+Ekm3= exp(-Yr3*L*10^3)

+alpha3=10*(log10(1/Ekm3));//Attenuation in dB/km

+disp(alpha1,"Attenuation in dB/km for (h=0.63 micro meter)")

+disp(alpha2,"Attenuation in dB/km for (h=1 micro meter)")

+disp(alpha3,"Attenuation in dB/km for (h=1.30 micro meter)")

+

+

diff --git a/2183/CH4/EX4.3/Ex_4_3.sce b/2183/CH4/EX4.3/Ex_4_3.sce
new file mode 100755
index 000000000..c486aec2e
--- /dev/null
+++ b/2183/CH4/EX4.3/Ex_4_3.sce
@@ -0,0 +1,13 @@
+// Example 4.3:Optical Powers

+clc;

+clear;

+close;

+h=1.5;//Wavelength in micro meter

+d=6;//Core diameter in micro meter

+v=600;//frequency in Mega Hertz

+alpha=0.4;//Attenuation in dB/km

+Pb=(4.4*10^-3*d^2*h^2*alpha*v*10^-3)*10^3;//Threshold optical power for brillouin scattering in milli Watt

+Pr=(5.9*10^-2*d^2*alpha*h);//Threshold optical power for Raman scattering in Watt

+disp(Pb,"Threshold optical power for Brillouin scattering in milli Watt")

+disp(Pr,"Threshold optical power for Raman scattering in Watt")

+//Pb is calculated wrong in the text book

diff --git a/2183/CH4/EX4.4.a/Ex_4_4_a.sce b/2183/CH4/EX4.4.a/Ex_4_4_a.sce
new file mode 100755
index 000000000..d8a19bb19
--- /dev/null
+++ b/2183/CH4/EX4.4.a/Ex_4_4_a.sce
@@ -0,0 +1,11 @@
+// Example 4.4.a:Critical Radius

+clc;

+clear;

+close;

+d=0.03;//Refractive index difference

+n1=1.5;//Core refractive index

+h= 0.85*10^-6;//Wavelength in meters

+x=2*n1^2*d;//

+Rc=(3*n1^2*h)/(4*%pi*sqrt(x))*10^6;// Critical Radius in micro meters

+disp(Rc,"Critical Radius in micro meters")

+//answer is calculated wrong in the textbook

diff --git a/2183/CH4/EX4.4.b/Ex_4_4_b.sce b/2183/CH4/EX4.4.b/Ex_4_4_b.sce
new file mode 100755
index 000000000..415d679c2
--- /dev/null
+++ b/2183/CH4/EX4.4.b/Ex_4_4_b.sce
@@ -0,0 +1,15 @@
+// Example 4.4.b:Critical Radius of curvature
+clc;
+clear;
+close;
+a=4;// core radius in micro meters
+d=0.003;//Refractive index difference
+n1=1.5;//Core refractive index
+h= 1.55*10^-6;//Wavelength in meters
+x=2*n1^2*d;//
+hc= ((2*%pi*a*10^-6*sqrt(2*d)*n1)/2.405)*10^6;//cut off wavelength in micro meters;
+x1=(20*h)/(sqrt(x));
+y=((2.748-0.996*((h*10^6)/hc)))^-3;
+Rcs=x1*y*10^6;
+disp(Rcs,"Critical Radius of curvature in micro meters")
+//answer is calculated wrong in the textbook
diff --git a/2183/CH4/EX4.5.a/Ex_4_5_a.sce b/2183/CH4/EX4.5.a/Ex_4_5_a.sce
new file mode 100755
index 000000000..d3d2cc468
--- /dev/null
+++ b/2183/CH4/EX4.5.a/Ex_4_5_a.sce
@@ -0,0 +1,8 @@
+// Example 4.5.a:Maximum possible optical bandwidth

+clc;

+clear;

+close;

+t=0.1*10^-6;//Time in second

+L=15;//Distance in km

+Bt=(1/(2*t))*10^-6;//Maximum possible optical bandwidth in Mega Hertz

+disp(Bt,"Maximum possible optical bandwidth in Mega Hertz")

diff --git a/2183/CH4/EX4.5.b/Ex_4_5_b.sce b/2183/CH4/EX4.5.b/Ex_4_5_b.sce
new file mode 100755
index 000000000..6dfa6af03
--- /dev/null
+++ b/2183/CH4/EX4.5.b/Ex_4_5_b.sce
@@ -0,0 +1,8 @@
+// Example 4.5.b:Despersion per unit length

+clc;

+clear;

+close;

+t=0.1*10^-6;//Time in second

+L=15;//Distance in km

+dp=(t/L)*10^6;//Despersion per unit length in micro second per Km

+disp(dp*10^3,"Despersion per unit length in nano second per km")

diff --git a/2183/CH4/EX4.5.c/Ex_4_5_c.sce b/2183/CH4/EX4.5.c/Ex_4_5_c.sce
new file mode 100755
index 000000000..f2920624c
--- /dev/null
+++ b/2183/CH4/EX4.5.c/Ex_4_5_c.sce
@@ -0,0 +1,9 @@
+// Example 4.5.c:Bandwidth legth product

+clc;

+clear;

+close;

+t=0.1*10^-6;//Time in second

+L=15;//Distance in km

+Bt=(1/(2*t))*10^-6;//Maximum possible optical bandwidth in Mega Hertz

+BL=Bt*L;// bandwidth length product in km

+disp(BL,"bandwidth length product in MHz km")

diff --git a/2183/CH4/EX4.6/Ex_4_6.sce b/2183/CH4/EX4.6/Ex_4_6.sce
new file mode 100755
index 000000000..b15959e6b
--- /dev/null
+++ b/2183/CH4/EX4.6/Ex_4_6.sce
@@ -0,0 +1,12 @@
+// Example 4.6;/Pulse broadning due to material dispersion

+clc;

+clear;

+close;

+c=3*10^5;// speed of light in km/s

+Dh=0.025;//Material dispersion

+L=1;//distance in km

+h=0.85;//Wavelength micro meters

+Sh=20;// Spectral width in nano meter

+M=Dh/(c*h*10^3);//

+Sm=M*L*Sh//Pulse broadning due to material dispersion in nano second per kilometer

+disp(Sm*10^9,"Pulse broadning due to material dispersion in nano second per kilometer")

diff --git a/2183/CH4/EX4.7/Ex_4_7.sce b/2183/CH4/EX4.7/Ex_4_7.sce
new file mode 100755
index 000000000..a230a4340
--- /dev/null
+++ b/2183/CH4/EX4.7/Ex_4_7.sce
@@ -0,0 +1,12 @@
+// Example 4.7//Pulse broadning due to material dispersion
+clc;
+clear;
+close;
+c=3*10^5;// speed of light in km/s
+Dh=0.03;//Material dispersion
+L=1;//distance in km
+h=0.85;//Wavelength in micro meters
+Sh=0.0012*h;// Spectral width in nano meter
+M=Dh/(c*h*10^3);//
+Sm=M*L*Sh//Pulse broadning due to material dispersion in nano second per kilometer
+disp(Sm*10^12,"Pulse broadning due to material dispersion in nano second per kilometer")
diff --git a/2183/CH4/EX4.8/Ex_4_8.sce b/2183/CH4/EX4.8/Ex_4_8.sce
new file mode 100755
index 000000000..a242ae2d2
--- /dev/null
+++ b/2183/CH4/EX4.8/Ex_4_8.sce
@@ -0,0 +1,12 @@
+// Example 4.8//Pulse broadning due to material dispersion
+clc;
+clear;
+close;
+ho=1343;//nm
+h=850;//in nm
+so=0.097;//in ps/nm^2
+m(h)=((so*(h/4))*(1-(h/ho))^4);// in ps/nm-km
+tgmat=m(h)*70;//in ns/km
+dt=tgmat*100;//in ns
+disp(dt,"total pulse spread in ns is")
+//answer is wrong in the textbook
diff --git a/2183/CH4/EX4.9.a/Ex_4_9_a.sce b/2183/CH4/EX4.9.a/Ex_4_9_a.sce
new file mode 100755
index 000000000..8398bfb19
--- /dev/null
+++ b/2183/CH4/EX4.9.a/Ex_4_9_a.sce
@@ -0,0 +1,10 @@
+// Example 4.9.a //delay

+clc;

+clear;

+close;

+d=0.01;// Change in refractive index

+n1=1.5;//Core refrctive index

+L=6*10^3;//Length in meter

+C=2.998*10^8;//Speed of light in m/s

+dts=round(((L*n1*d)/C)*10^9);//delay in ns

+disp(dts,"delay in ns")

diff --git a/2183/CH4/EX4.9.b/Ex_4_9_b.sce b/2183/CH4/EX4.9.b/Ex_4_9_b.sce
new file mode 100755
index 000000000..85fd6a15e
--- /dev/null
+++ b/2183/CH4/EX4.9.b/Ex_4_9_b.sce
@@ -0,0 +1,10 @@
+// Example 4.9.b;//Pulse broadning due to intermodal dispersion

+clc;

+clear;

+close;

+d=0.01;// Change in refractive index

+n1=1.5;//Core refrctive index

+L=6*10^3;//Length in meter

+C=2.998*10^8;//Speed of light in m/s

+Ss=(L*n1*d)/(2*sqrt(3)*C)*10^9;//Pulse broadning due to intermodal dispersion in ns

+disp(Ss,"Pulse broadning due to intermodal dispersion in ns")

diff --git a/2183/CH4/EX4.9.c/Ex_4_9_c.sce b/2183/CH4/EX4.9.c/Ex_4_9_c.sce
new file mode 100755
index 000000000..e1a0b0dc8
--- /dev/null
+++ b/2183/CH4/EX4.9.c/Ex_4_9_c.sce
@@ -0,0 +1,14 @@
+// Example 4.9.c//Bit Rate

+clc;

+clear;

+close;

+d=0.01;// Change in refractive index

+n1=1.5;//Core refrctive index

+L=6*10^3;//Length in meter

+C=2.998*10^8;//Speed of light in m/s

+dts=round(((L*n1*d)/C)*10^9);//Delay in ns

+Bt=(1/(2*dts*10^9))*10^12;//Bit rate in Mbits/sec

+Ss=(L*n1*d)/(2*sqrt(3)*C);//Pulse broadning due to intermodal dispersion in ns

+Btimp=0.2/Ss;//

+disp(Bt,"Bit rate in M bit per seconds")

+disp(Btimp*10^-6,"improved estimate of bit rate in M bit per seconds")

diff --git a/2183/CH4/EX4.9.d/Ex_4_9_d.sce b/2183/CH4/EX4.9.d/Ex_4_9_d.sce
new file mode 100755
index 000000000..69e0e522f
--- /dev/null
+++ b/2183/CH4/EX4.9.d/Ex_4_9_d.sce
@@ -0,0 +1,14 @@
+// Example 4.9.d//BANDWIDTH LENGTH PRODUCT
+clc;
+clear;
+close;
+d=0.01;// Change in refractive index
+n1=1.5;//Core refrctive index
+L=6*10^3;//Length in meter
+C=2.998*10^8;//Speed of light in m/s
+dts=round(((L*n1*d)/C)*10^9);//Delay in ns
+Bt=(1/(2*dts*10^9))*10^12;//Bit rate in Mbits/sec
+Ss=(L*n1*d)/(2*sqrt(3)*C);//Pulse broadning due to intermodal dispersion in ns
+Btimp=0.2/Ss;//
+BL=Btimp*L*10^-9;// bandwidth length product in km
+disp(BL,"bandwidth length product MHz km")
diff --git a/2183/CH5/EX5.1/Ex_5_1.sce b/2183/CH5/EX5.1/Ex_5_1.sce
new file mode 100755
index 000000000..9e969fe78
--- /dev/null
+++ b/2183/CH5/EX5.1/Ex_5_1.sce
@@ -0,0 +1,13 @@
+// Example 5.1 //number of longitudinal modes and frequency spacing

+clc;

+clear;

+close;

+h=0.55*10^-6;//Wavelength in meter

+n=1.78;//refractive index

+L=4*10^-2;//Length in meter

+C=3*10^8;//Speed of light in m/s

+q=(2*n*L)/(h);//Number of logitudinal modes

+df=((C)/(2*n*L))*10^-9;//frequency sepration in Gega Hertz

+disp(q,"Number of longitudinal modes are ")

+disp(df,"frequency spacing in Gega Hertz is ")

+

diff --git a/2183/CH5/EX5.2/Ex_5_2.sce b/2183/CH5/EX5.2/Ex_5_2.sce
new file mode 100755
index 000000000..8ce6c089a
--- /dev/null
+++ b/2183/CH5/EX5.2/Ex_5_2.sce
@@ -0,0 +1,11 @@
+// Example 5.2;//wavelength spacing and frequency spacing

+clc;

+clear;

+close;

+Br1=7.21*10^-10;//Bit rate

+n=10^18;//hole concentration

+Trg=((Br1*n)^-1)*10^9;//radiative minority carrier lifetime in GaAs in ns

+Br2=1.79*10^-15;//Bit rate

+Trs=((Br2*n)^-1)*10^3;//radiative minority carrier lifetime in Si in ms

+disp(Trg,"radiative minority carrier lifetime in GaAs in ns")

+disp(Trs,"radiative minority carrier lifetime in Si in ms")

diff --git a/2183/CH5/EX5.3/Ex_5_3.sce b/2183/CH5/EX5.3/Ex_5_3.sce
new file mode 100755
index 000000000..2fe6ac70c
--- /dev/null
+++ b/2183/CH5/EX5.3/Ex_5_3.sce
@@ -0,0 +1,14 @@
+

+// Example 5.3 //threshold density and threshold current

+clc;

+clear;

+close;

+B=21*10^-3;//Gain factor in ampere per centimeter cube

+alpha=10;// in per cm

+L=250*10^-4;//length in meter

+w=100;//in micro meter

+r=0.32;

+Jth=(1/B)*(alpha+(1/L)*log(1/r));//Threshold current in ampere per centimeter cube

+ith=Jth*L*w*10^-4;//

+disp(Jth,"threshold density in Ampere per centimeter square")

+disp(ith*10^3,"threshold current in mA is")

diff --git a/2183/CH5/EX5.4/Ex_5_4.sce b/2183/CH5/EX5.4/Ex_5_4.sce
new file mode 100755
index 000000000..e6f78298e
--- /dev/null
+++ b/2183/CH5/EX5.4/Ex_5_4.sce
@@ -0,0 +1,9 @@
+// Example 5.4 //slope efficiency
+clc;
+clear;
+close;
+eg=1242;//
+e=1300;//in nm
+n=0.1;//efficiency
+s=((eg/e)*n);//
+disp(s,"slope efficiency is")
diff --git a/2183/CH5/EX5.5/Ex_5_5.sce b/2183/CH5/EX5.5/Ex_5_5.sce
new file mode 100755
index 000000000..a5dd0ccb9
--- /dev/null
+++ b/2183/CH5/EX5.5/Ex_5_5.sce
@@ -0,0 +1,9 @@
+// Example 5.5//external power efficiency
+clc;
+clear;
+close;
+eg=1.44;//
+v=2.8;//in volts
+an=0.20;;//efficiency
+nep=((an*(eg/v))*100);//external power efficiency 
+disp(nep,"external power efficiency in percentage is")
diff --git a/2183/CH5/EX5.6/Ex_5_6.sce b/2183/CH5/EX5.6/Ex_5_6.sce
new file mode 100755
index 000000000..c3f24452f
--- /dev/null
+++ b/2183/CH5/EX5.6/Ex_5_6.sce
@@ -0,0 +1,12 @@
+// Example 5.6;//ratio of threshold current at differnt temperatures

+clc;

+close;

+clear;

+To1=160;//Absolute temperature in Kelvin

+To=55;//in Kelvin

+T1=293;//T=20 in Kelvin

+T2=353;//T=80 in Kelvin

+J1=exp((T2-T1)/To1);//threshold current ration for AlGaAs laser

+J2=exp((T2-T1)/To);//threshold current RATIO FOR InGaAs laser

+disp(J1,"ratio of the threshold current densities for AlGaAs laser")

+disp(J2,"ratio of current densities for InGaAs laser")

diff --git a/2183/CH5/EX5.7.a/Ex_5_7_a.sce b/2183/CH5/EX5.7.a/Ex_5_7_a.sce
new file mode 100755
index 000000000..ab4e00473
--- /dev/null
+++ b/2183/CH5/EX5.7.a/Ex_5_7_a.sce
@@ -0,0 +1,12 @@
+// Example 5.7.a;//rms value of power fluctuation
+clc;
+close;
+clear;
+op=10^-15;//outputin dB Hz^-1
+bw=100;//in MHz
+h=1.55;//in micro meter
+ef=0.6;//quantum efficiency
+pi=2;//in mW
+rrmf=op*bw*10^6;//
+rmf=sqrt(rrmf);//
+disp(rmf,"rms value of power fluctuation is")
diff --git a/2183/CH5/EX5.7.b/Ex_5_7_b.sce b/2183/CH5/EX5.7.b/Ex_5_7_b.sce
new file mode 100755
index 000000000..1eeb21967
--- /dev/null
+++ b/2183/CH5/EX5.7.b/Ex_5_7_b.sce
@@ -0,0 +1,16 @@
+// Example 5.7.b;//rms noise current
+clc;
+close;
+clear;
+op=10^-15;//outputin dB Hz^-1
+bw=100;//in MHz
+h=1.55;//in micro meter
+ef=0.6;//quantum efficiency
+pi=2;//in mW
+rrmf=op*bw*10^6;//
+rmf=sqrt(rrmf);//
+e=1.6*10^-19;//
+hc=6.63*10^-34;//
+c=3*10^8;//in m/s
+x=((e*ef*h*10^-6*pi*10^-3*10^4*3.16*10^-8)/(hc*c));//
+disp(x,"rms noise current in A is")
diff --git a/2183/CH6/EX6.1/Ex_6_1.sce b/2183/CH6/EX6.1/Ex_6_1.sce
new file mode 100755
index 000000000..0cb810bff
--- /dev/null
+++ b/2183/CH6/EX6.1/Ex_6_1.sce
@@ -0,0 +1,9 @@
+// Example 6.1 //inernal quantum efficiency

+clc;

+clear;

+close;

+tr=2.5;//radiative recombination time in milli second

+tnr=50;//non radiative recombination time in milli second

+t=(tr*tnr)/(tr+tnr);//Bulk recombination life time in millisecond

+nint= (t/tr)

+disp(nint*100,"inernal quantum efficiency is(%) ")

diff --git a/2183/CH6/EX6.10/Ex_6_10.sce b/2183/CH6/EX6.10/Ex_6_10.sce
new file mode 100755
index 000000000..bb3f412ad
--- /dev/null
+++ b/2183/CH6/EX6.10/Ex_6_10.sce
@@ -0,0 +1,9 @@
+// Example 6.10 //power coupled
+clc;
+clear;
+close;
+tha=15;//in degree
+po=1;//in micro watt
+nc=(sind(tha))^2;//
+pf=nc*po*10^-6;//in watts
+disp(pf*10^9,"power coupled in nW is")
diff --git a/2183/CH6/EX6.11/Ex_6_11.sce b/2183/CH6/EX6.11/Ex_6_11.sce
new file mode 100755
index 000000000..967e5c0db
--- /dev/null
+++ b/2183/CH6/EX6.11/Ex_6_11.sce
@@ -0,0 +1,13 @@
+// Example 6.11 //power coupled
+clc;
+clear;
+close;
+If=1.5;//in mA
+Vf=20;//in volts
+pin=If*Vf;//in Watts
+nint=2;//efficiency    
+tha=20;//in degree
+po=((nint/100)*pin);//in Watt
+nc=(sind(tha))^2;//
+pf=nc*po;//in Watts
+disp(pf*10^3,"power coupled in micro watts is")
diff --git a/2183/CH6/EX6.12/Ex_6_12.sce b/2183/CH6/EX6.12/Ex_6_12.sce
new file mode 100755
index 000000000..0d3879f58
--- /dev/null
+++ b/2183/CH6/EX6.12/Ex_6_12.sce
@@ -0,0 +1,7 @@
+// Example 6.12;//bandwidth
+clc;
+clear;
+close;
+tr=10;//in ns
+bw=(0.35/tr);//in MHz
+disp(bw*10^3,"bandwidth in MHz is")
diff --git a/2183/CH6/EX6.13/Ex_6_13.sce b/2183/CH6/EX6.13/Ex_6_13.sce
new file mode 100755
index 000000000..a22b9b043
--- /dev/null
+++ b/2183/CH6/EX6.13/Ex_6_13.sce
@@ -0,0 +1,14 @@
+// Example 6.13 //coupling efficiency
+clc;
+clear;
+close;
+t=1;//
+no=1;//
+na=0.3;//
+x=1;//assume
+y=1;//
+nc1=(t*(na/no)^2*(x/y)^2)*100;//
+alpha=2;//
+nc2=((t*(na/no)^2*(x/y)^2*(alpha/(alpha+2))))*100;//
+disp(nc1,"coupling efficiency for step index fiber in (%)")
+disp(nc2,"coupling efficiency for graded index fiber in (%)")
diff --git a/2183/CH6/EX6.14/Ex_6_14.sce b/2183/CH6/EX6.14/Ex_6_14.sce
new file mode 100755
index 000000000..51cd9d3d4
--- /dev/null
+++ b/2183/CH6/EX6.14/Ex_6_14.sce
@@ -0,0 +1,12 @@
+// Example 6.14 //coupling efficiency
+clc;
+clear;
+close;
+t=1;//
+no=1;//
+na=0.3;//
+x=1;//assume
+y=3/4;//
+alpha=2;//
+nc1=((t*(na/no)^2)*(alpha+(1-(y/x)^2)))/(alpha+2)*100;//
+disp(nc1,"coupling efficiency for graded index fiber in (%)")
diff --git a/2183/CH6/EX6.15/Ex_6_15.sce b/2183/CH6/EX6.15/Ex_6_15.sce
new file mode 100755
index 000000000..506c9a24d
--- /dev/null
+++ b/2183/CH6/EX6.15/Ex_6_15.sce
@@ -0,0 +1,9 @@
+// Example 6.15;//power coupled
+clc;
+clear;
+close;
+n1=1.48;//
+n2=1.46;//
+po=100;//in micro watts
+pin=((po*((n1^2-n2^2))));//in micro watts
+disp(pin,"power coupled in micro watts is")
diff --git a/2183/CH6/EX6.2/Ex_6_2.sce b/2183/CH6/EX6.2/Ex_6_2.sce
new file mode 100755
index 000000000..662d2f756
--- /dev/null
+++ b/2183/CH6/EX6.2/Ex_6_2.sce
@@ -0,0 +1,15 @@
+// Example 6.2//internal power level

+clc;

+clear;

+close;

+e=1.6*10^-19;//Electronic charge

+ht=6.62*10^-34;//Constt

+C=3*10^8;//speed light in m/s

+h=0.87*10^-6;//wavelength in meter

+tr=80;//radiative recombination time in nano second

+tnr=120;//non radiative recombination time in nano second

+t=(tr*tnr)/(tr+tnr);//Bulk recombination life time in nano second

+nint= (t/tr)

+i=40;//injected current in milli ampere

+Pint= (nint*((ht*C*i*10^-3)/(e*h)))*10^3;//internal power level in milli Watt

+disp(Pint,"internal power level in milli Watt")

diff --git a/2183/CH6/EX6.3.a/Ex_6_3_a.sce b/2183/CH6/EX6.3.a/Ex_6_3_a.sce
new file mode 100755
index 000000000..948a819b6
--- /dev/null
+++ b/2183/CH6/EX6.3.a/Ex_6_3_a.sce
@@ -0,0 +1,9 @@
+// Example 6.3.a//optical power emitted

+clc;

+clear;

+close;

+F=0.62;//transmission factore

+nx=3.6;//refractive index

+n=1;//refractive index of air

+Px=((F*n^2)/(4*nx^2));//optical power emitter

+disp("emiiter power in terms of power generated internally is "+string(Px)+" Pint")

diff --git a/2183/CH6/EX6.3.b/Ex_6_3_b.sce b/2183/CH6/EX6.3.b/Ex_6_3_b.sce
new file mode 100755
index 000000000..6b28a1e5b
--- /dev/null
+++ b/2183/CH6/EX6.3.b/Ex_6_3_b.sce
@@ -0,0 +1,11 @@
+// Example 6.3.b //external power efficiency
+clc;
+clear;
+close;
+F=0.62;//transmission factore
+nx=3.6;//refractive index
+n=1;//refractive index of air
+Px=((F*n^2)/(4*nx^2));//optical power emitter
+Pint=0.5;//
+NEP=(Px*Pint)*100;//
+disp(NEP,"external power efficiency in (%) is")
diff --git a/2183/CH6/EX6.4.a/Ex_6_4_a.sce b/2183/CH6/EX6.4.a/Ex_6_4_a.sce
new file mode 100755
index 000000000..685134a86
--- /dev/null
+++ b/2183/CH6/EX6.4.a/Ex_6_4_a.sce
@@ -0,0 +1,8 @@
+// Example 6.4.a //coupling efficiency

+clc;

+clear;

+close;

+NA=0.2;//numerical aperture

+n=1.4;//refractive index

+nc=(NA)^2;//coupling efficiency

+disp(nc,"coupling efficiency is")

diff --git a/2183/CH6/EX6.4.b/Ex_6_4_b.sce b/2183/CH6/EX6.4.b/Ex_6_4_b.sce
new file mode 100755
index 000000000..381865e9e
--- /dev/null
+++ b/2183/CH6/EX6.4.b/Ex_6_4_b.sce
@@ -0,0 +1,9 @@
+// Example 6.4.b //optical power loss

+clc;

+clear;

+close;

+NA=0.2;//numerical aperture

+n=1.4;//refractive index

+nc=(NA)^2;//coupling efficiency

+Loss=round(-(10*log10(nc)));//optical loss in dB

+disp(Loss,"optical loss in dB is")

diff --git a/2183/CH6/EX6.4.c/Ex_6_4_c.sce b/2183/CH6/EX6.4.c/Ex_6_4_c.sce
new file mode 100755
index 000000000..b8c774466
--- /dev/null
+++ b/2183/CH6/EX6.4.c/Ex_6_4_c.sce
@@ -0,0 +1,12 @@
+// Example 6.4.c //optical  loss
+clc;
+clear;
+close;
+NA=0.2;//numerical aperture
+n=1.4;//refractive index
+nc=(NA)^2;//coupling efficiency
+pe=0.012;//
+pc1=pe*nc;//
+Loss=round(-(10*log10(pc1)));//optical loss in dB
+disp(Loss,"optical loss in dB is")
+//answer is wrong in the text book
diff --git a/2183/CH6/EX6.5/Ex_6_5.sce b/2183/CH6/EX6.5/Ex_6_5.sce
new file mode 100755
index 000000000..b0c1149a2
--- /dev/null
+++ b/2183/CH6/EX6.5/Ex_6_5.sce
@@ -0,0 +1,12 @@
+// Example 6.5 //optical power 

+clc;

+clear;

+close;

+r=0.01;//fresenel reflection coefficient

+NA=0.15;//numeical apertrure

+Rd=30;//radiance in W sr-1 cm-2

+R=30*10^-4;//radis in centi meter

+A=(%pi*R^2);//area 

+Pc=(%pi*(1-r)*A*Rd*NA^2)*10^6;//optical power coupled in mincro watt

+disp(Pc,"optical power coupled in micro Watt is")

+// answer is wrong in the textbook

diff --git a/2183/CH6/EX6.6/Ex_6_6.sce b/2183/CH6/EX6.6/Ex_6_6.sce
new file mode 100755
index 000000000..8c8cb741a
--- /dev/null
+++ b/2183/CH6/EX6.6/Ex_6_6.sce
@@ -0,0 +1,12 @@
+

+// Example 6.6 //overall power conversion efficiency 

+clc;

+clear;

+close;

+Pc=200*10^-6;//Optical power in Watt

+If=25;//forward current in milli Ampere

+Vf=1.5;//forward voltage in Volts

+P=If*10^-3*Vf;//power in Watt

+npc=((Pc/P));//overall power conversion efficiency

+disp(npc*100,"overall power conversion efficiency in percentage")

+//answer is wrong in the textbook

diff --git a/2183/CH6/EX6.7/ex_6_7.sce b/2183/CH6/EX6.7/ex_6_7.sce
new file mode 100755
index 000000000..e78550724
--- /dev/null
+++ b/2183/CH6/EX6.7/ex_6_7.sce
@@ -0,0 +1,8 @@
+// Example 6.7:compare
+clc;
+clear;
+close;
+ioi=1/sqrt(2);//given
+ioi1=1/(2);//given/
+disp(ioi,"-3 dB electrical bandwidth point occur when Iout/Iin,=")
+disp(ioi1,"-3 dB optical bandwidth point occur when Iout/Iin,=")
diff --git a/2183/CH6/EX6.8/Ex_6_8.sce b/2183/CH6/EX6.8/Ex_6_8.sce
new file mode 100755
index 000000000..40a0fd0ec
--- /dev/null
+++ b/2183/CH6/EX6.8/Ex_6_8.sce
@@ -0,0 +1,16 @@
+// Example 6.8 //find output power and bandwidth

+clc;

+clear;

+close;

+Pdc=320*10^-6;//d.c. power in Watt

+f1=20*10^6;//frequency in hertz

+Ti=5*10^-9;//recombination life time in nano second

+Pe1=(Pdc/sqrt(1+(2*%pi*f1*Ti)^2))*10^6;

+f2=100*10^6;//frequency in hertz

+Pe2=(Pdc/sqrt(1+(2*%pi*f2*Ti)^2))*10^6;

+f=((sqrt(3))/(2*%pi*Ti));//in MHz

+fele=f*0.707;//

+disp(Pe1,"overall power in micro Watt when frequecy is 20 MHz")

+disp(Pe2,"overall power in micro Watt when frequecy is 80 MHz")

+disp(f*10^-6,"optical bandwidth in MHz is")

+disp(round(fele*10^-6),"electrical bandwidth in MHz is")

diff --git a/2183/CH6/EX6.9/Ex_6_9.sce b/2183/CH6/EX6.9/Ex_6_9.sce
new file mode 100755
index 000000000..ae1a2d5eb
--- /dev/null
+++ b/2183/CH6/EX6.9/Ex_6_9.sce
@@ -0,0 +1,13 @@
+// Example 6.9;//CW operating lifetime
+clc;
+clear;
+close;
+d=0.67;//
+bo=1.86*10^7;//in h^-1
+ea=1.67*10^-19;//
+k=1.38*10^-23;//
+t=290;//Kelvin
+x=((-ea)/(k*t));//
+be=((bo)*exp(-40));//in h^-1
+t=((-log(d))/be);//in hours
+disp(t,"CW operating lifetime in hours is")
diff --git a/2183/CH7/EX7.1/Ex_7_1.sce b/2183/CH7/EX7.1/Ex_7_1.sce
new file mode 100755
index 000000000..b9149d936
--- /dev/null
+++ b/2183/CH7/EX7.1/Ex_7_1.sce
@@ -0,0 +1,10 @@
+// Example 7.1 //WAVELENGTH

+clc;

+clear;

+close;

+E=1.35//energy gap in electron-volt

+e=1.6*10^-19;//elecronic charge

+C=3*10^8;//Speed of light in meter per second

+ht=6.63*10^-34;//plank constt.

+h=((ht*C)/(E*e))*10^6;//Wavelength

+disp(h,"wavelength in micro meter")

diff --git a/2183/CH7/EX7.10/Ex_7_10.sce b/2183/CH7/EX7.10/Ex_7_10.sce
new file mode 100755
index 000000000..a4e4aacaa
--- /dev/null
+++ b/2183/CH7/EX7.10/Ex_7_10.sce
@@ -0,0 +1,9 @@
+//Example 7.10 // Bandwidth
+clc;
+clear;
+close;
+//given data :
+t_tr=100;// in ps
+tau_rc=100;// in ps
+BW=(1/(2*%pi*(t_tr+tau_rc)*10^-12))*10^-9;
+disp(BW,"Bandwidth,BW(G bit/s) = ")
diff --git a/2183/CH7/EX7.11/Ex_7_11.sce b/2183/CH7/EX7.11/Ex_7_11.sce
new file mode 100755
index 000000000..3370d7afc
--- /dev/null
+++ b/2183/CH7/EX7.11/Ex_7_11.sce
@@ -0,0 +1,16 @@
+//Example 7.11 // Multiplication factor
+clc;
+clear;
+close;
+//given data :
+eta=80/100;// quantum efficiency
+e=1.6*10^-19;
+lamda=.88*10^-6;// in m
+h=6.63*10^-34;// 
+c=3*10^8;
+I=12;// in micro-A
+R=(eta*e*lamda)/(h*c);
+P0=0.6*10^-6;// in W
+Ip=P0*R*10^6;
+M=I/Ip;
+disp(M,"Multiplication factor,M = ")
diff --git a/2183/CH7/EX7.12/Ex_7_12.sce b/2183/CH7/EX7.12/Ex_7_12.sce
new file mode 100755
index 000000000..e5234ec92
--- /dev/null
+++ b/2183/CH7/EX7.12/Ex_7_12.sce
@@ -0,0 +1,17 @@
+//Example 7.12 // Optical gain and hFE
+clc;
+clear;
+close;
+//given data :
+h=6.63*10^-34;
+c=3*10^8;
+e=1.6*10^-19;
+Ic=15*10^-3;// in A
+P0=140*10^-6;// in W
+lamda=1.3*10^-6;// in m
+eta=45/100;// quantum efficiency
+G0=(h*c*Ic)/(e*P0*lamda);
+disp(G0,"The optical gain,G0 = ")
+h_FE=G0/eta;
+disp(h_FE,"hFE = ")
+// answer is wrong in the textbook
diff --git a/2183/CH7/EX7.13/Ex_7_13.sce b/2183/CH7/EX7.13/Ex_7_13.sce
new file mode 100755
index 000000000..4020ea3cd
--- /dev/null
+++ b/2183/CH7/EX7.13/Ex_7_13.sce
@@ -0,0 +1,10 @@
+//Example 7.13 // Maximum 3dB bandwidth
+clc;
+clear;
+close;
+//given data :
+tF=5*10^-12;// in sec
+G=60;// photoconductive gain
+Bm=(1/(2*%pi*tF*G))*10^-6;
+disp(Bm,"The maximum 3dB bandwidth,Bm(MHz) = ")
+// answer is wrong in textbook
diff --git a/2183/CH7/EX7.14/Ex_7_14.sce b/2183/CH7/EX7.14/Ex_7_14.sce
new file mode 100755
index 000000000..fc1853cff
--- /dev/null
+++ b/2183/CH7/EX7.14/Ex_7_14.sce
@@ -0,0 +1,9 @@
+//Example 7.14 // SNR
+clc;
+clear;
+close;
+r=1;//responsivity
+p=0.1;//micro watt
+ins=910;//nA
+snr=((r^2*(p*10^3)^2)/(ins^2));//
+disp(snr,"SNR is, =")
diff --git a/2183/CH7/EX7.2/Ex_7_2.sce b/2183/CH7/EX7.2/Ex_7_2.sce
new file mode 100755
index 000000000..378722185
--- /dev/null
+++ b/2183/CH7/EX7.2/Ex_7_2.sce
@@ -0,0 +1,16 @@
+

+// Example 7.2 //quantum efficiency and responsivity

+clc;

+clear;

+close;

+e=1.6*10^-19;//elecronic charge

+re=1.2*10^12;// Average no. of electron hole pair generated

+rp=3*10^12;//no. of photons

+h=0.85;//wavelength in micro meter

+E=0.75;//energy gap in electron volt

+C=3*10^8;//SPEED of light in meter per second

+n=round((re/rp)*100);//quantum efficiency

+ht=6.62*10^-34;//plank constt.

+R=((n/100)*e*h*10^-6)/(ht*C);

+disp(n,"quantum efficiency (%)")

+disp(R,"Responsivity is in Ampere per Watt")

diff --git a/2183/CH7/EX7.3/Ex_7_3.sce b/2183/CH7/EX7.3/Ex_7_3.sce
new file mode 100755
index 000000000..de5daf3ca
--- /dev/null
+++ b/2183/CH7/EX7.3/Ex_7_3.sce
@@ -0,0 +1,15 @@
+// Example 7.3 //Wavelength and Incident optical power

+clc;

+clear;

+close;

+E=1.5*10^-19;//energy in joule

+e=1.6*10^-19;//elecronic charge

+If=3*10^-6;//forward current in ampere

+C=3*10^8;//Speed of light in meter per second

+n=0.6;//quantum efficiency

+ht=6.62*10^-34;//plank constt.

+h=((ht*C)/E)*10^6;//Wavelength

+R=(n*e)/(E);//Responsivity in ampere per watt

+Po=(If/R)*10^6;//Output power in micro watt

+disp(h,"wavelength in micro meter")

+disp(Po,"Output power in micro Watt")

diff --git a/2183/CH7/EX7.4/Ex_7_4.sce b/2183/CH7/EX7.4/Ex_7_4.sce
new file mode 100755
index 000000000..1894380ac
--- /dev/null
+++ b/2183/CH7/EX7.4/Ex_7_4.sce
@@ -0,0 +1,12 @@
+
+// Example 7.4 //responsivity
+clc;
+clear;
+close;
+n=20;//efficiency
+e=1.6*10^-19;//elecronic charge
+h=0.80;//wavelength in micro meter
+C=3*10^8;//SPEED of light in meter per second
+ht=6.62*10^-34;//plank constt.
+R=((n/100)*e*h*10^-6)/(ht*C);
+disp(R,"Responsivity is in Ampere per Watt")
diff --git a/2183/CH7/EX7.5.a/Ex_7_5_a.sce b/2183/CH7/EX7.5.a/Ex_7_5_a.sce
new file mode 100755
index 000000000..7f57833c3
--- /dev/null
+++ b/2183/CH7/EX7.5.a/Ex_7_5_a.sce
@@ -0,0 +1,9 @@
+// Example 7.5.a //photocurrent
+clc;
+clear;
+close;
+R=0.85;//in AW^-1
+pi=1.5;//in mW
+po=1;//in mW
+ip=po*R;//in mA
+disp(ip,"photocurrent in mA is")
diff --git a/2183/CH7/EX7.6/Ex_7_6.sce b/2183/CH7/EX7.6/Ex_7_6.sce
new file mode 100755
index 000000000..51824e0cc
--- /dev/null
+++ b/2183/CH7/EX7.6/Ex_7_6.sce
@@ -0,0 +1,9 @@
+// Example 7.6 // responsivity
+clc;
+clear;
+close;
+e=1.6*10^-19;//elecronic charge
+eg=0.75;//eV
+n=0.7;//
+R=(n*e)/(eg*e);//
+disp(R,"Responsivity is in Ampere per Watt")
diff --git a/2183/CH7/EX7.7/Ex_7_7.sce b/2183/CH7/EX7.7/Ex_7_7.sce
new file mode 100755
index 000000000..49547776b
--- /dev/null
+++ b/2183/CH7/EX7.7/Ex_7_7.sce
@@ -0,0 +1,8 @@
+// Example 7.7 //width  of deplition region
+clc;
+clear;
+close;
+n=70;//efficinecy
+absc=10^5;//cm^-1
+W=(2.303*-log10(1-(n/100)))/(absc);//in meter
+disp(round(W*10^6),"deplition width in micro meter is")
diff --git a/2183/CH7/EX7.8/Ex_7_8.sce b/2183/CH7/EX7.8/Ex_7_8.sce
new file mode 100755
index 000000000..1afda51ea
--- /dev/null
+++ b/2183/CH7/EX7.8/Ex_7_8.sce
@@ -0,0 +1,10 @@
+//Example 7.8 // Maximum response time
+clc;
+clear;
+close;
+//given data :
+Vd=3*10^4;// in m/s
+W=30*10^-6;// in m
+Bm=Vd/(2*%pi*W);
+M=(1/Bm)*10^9;
+disp(M,"Maximum response time,(ns) = ")
diff --git a/2183/CH7/EX7.9/Ex_7_9.sce b/2183/CH7/EX7.9/Ex_7_9.sce
new file mode 100755
index 000000000..4919f9795
--- /dev/null
+++ b/2183/CH7/EX7.9/Ex_7_9.sce
@@ -0,0 +1,16 @@
+//Example 7.9 // NEP and specific detectivity
+clc;
+clear;
+close;
+//given data :
+h=6.63*10^-34;
+c=3*10^8;
+Id=9*10^-9;// in A
+e=1.6*10^-19;
+eta=60/100;
+lamda=1.3*10^-6;// in m
+A=100*50*10^-12;// in m^2
+NEP=(h*c*sqrt(2*Id*e))/(eta*e*lamda);
+disp(NEP,"NEP,(W) = ")
+D=sqrt(A)/NEP;
+disp(D,"Specific detectivity,(MHz^(-1/2) W^-1) = ")
diff --git a/2183/CH8/EX8.1/Ex_8_1.sce b/2183/CH8/EX8.1/Ex_8_1.sce
new file mode 100755
index 000000000..69481a0e5
--- /dev/null
+++ b/2183/CH8/EX8.1/Ex_8_1.sce
@@ -0,0 +1,36 @@
+

+// Example 8.1 //compare shot noise and thermal current

+clc;

+clear;

+close;

+T=293;//Temperature in Kelvin

+K=1.38*10^-23;//boltzman constt

+C=3*10^8;//Speed of light in meter per second

+e=1.6*10^-19;//elecronic charge

+ht=6.62*10^-34;//plank constt.

+Id=3;//dark current in nano ampere

+n=0.60;//efficiency

+Rl=4;//load resistance in kilo-ohms

+h=0.9;//wavelength in micro meter

+Po=200;// ouput power in nano Watt

+B=5;// bandwidth in mega hertz

+Ip= ((n*h*10^-6*Po*10^-9*e)/(ht*C))*10^9;//Photo current in Ampere

+its=(2*e*B*10^6*(Id+Ip)*10^-9);//total shot noise

+itsr=sqrt(its);//RMS shot noise

+disp(itsr,"RMS shot noise current in Ampere is")

+T=293;//Temperature in Kelvin

+K=1.38*10^-23;//boltzman constt

+C=3*10^8;//Speed of light in meter per second

+e=1.6*10^-19;//elecronic charge

+ht=6.62*10^-34;//plank constt.

+Id=3;//dark current in nano ampere

+n=0.60;//efficiency

+Rl=4;//load resistance in killo ohms

+h=0.9;//wavelength in micro meter

+Po=200;// ouput power in nano wat

+B=5;// bandwidth in mega hertz

+it=(((4*K*T*B*10^6)/(Rl*10^3)));//thermal noise

+itr=sqrt(it);//rms thermal noise

+disp(itr,"RMS thermal noise current in Ampere is")

+

+

diff --git a/2183/CH8/EX8.10/Ex_8_10.sce b/2183/CH8/EX8.10/Ex_8_10.sce
new file mode 100755
index 000000000..2754dcc9e
--- /dev/null
+++ b/2183/CH8/EX8.10/Ex_8_10.sce
@@ -0,0 +1,19 @@
+// Example 8.10 //optical power budget
+clc;
+clear;
+close;
+mip=-10;//dBm
+mop=-41;//dBm
+tsm=mip-mop;//dB
+disp(tsm,"total system margin in dB is")
+l=7;//km
+fcl=2.6;//dB
+lfc=l*fcl;//fiber cable loss in dB
+sl=0.5;//dBm
+slc=sl*(l-1);//dB
+cl=1.5;//dB
+sm=6;//dB
+tsm1=lfc+slc+cl+sm;//dB
+disp(tsm1,"total system margin in dB is")
+epm=tsm-tsm1;//dB
+disp(epm,"excess power margin in dB is")
diff --git a/2183/CH8/EX8.12/Ex_8_12.sce b/2183/CH8/EX8.12/Ex_8_12.sce
new file mode 100755
index 000000000..678050bd8
--- /dev/null
+++ b/2183/CH8/EX8.12/Ex_8_12.sce
@@ -0,0 +1,24 @@
+// Example 8.12 //optical power
+clc;
+clear;
+close;
+e=1.6*10^-19;//electron charge
+sndb=55;//signal to noise ration in dB
+sn=(10^(sndb/10));//
+bw=5;//Mhz
+r=0.5;//responsivity
+cs=0.7;//signal attenuation
+k=1.38*10^-23;//bolzman constant
+tc=20;//degree celsius
+tk=tc+273;//Kelvin
+fdb=1.5;//
+f=10^(fdb/10);//
+rl=1;//mega ohms
+x=((sn*4*k*tk*bw*10^6*f)/(rl*10^6));//
+y=((2*sn*e*bw*10^6*r));//
+ma=9/8;//
+z=(2*ma*r^2*cs^2);//
+s=poly(0,"s");//
+p=-x-y*s+z*s^2;//
+m=roots(p);//
+disp(m(1,1)*10^6,"average incident power in micro Watts is")
diff --git a/2183/CH8/EX8.13/Ex_8_13.sce b/2183/CH8/EX8.13/Ex_8_13.sce
new file mode 100755
index 000000000..b6e7acdfb
--- /dev/null
+++ b/2183/CH8/EX8.13/Ex_8_13.sce
@@ -0,0 +1,20 @@
+// Example 8.13 //optical power
+clc;
+clear;
+close;
+fdb=6;//
+f=10^(fdb/10);//
+e=1.6*10^-19;//electron charge
+sndb=45;//signal to noise ration in dB
+sn=(10^(sndb/10));//
+h=6.63*10^-34;//planck constant
+c=3*10^8;//m/s
+e=1.6*10^-19;//
+n=0.6;//efficneicny
+ma=0.5*10^-3;//
+k=1.38*10^-23;//boltzman constant
+tk=300;//degree celcius
+bw=8;//MHz
+rl=50;//kilo ohms
+po=((h*c)/(e*n*ma^2))*sqrt((8*k*tk*bw*10^6*f)/(rl*10^3))*sqrt(sn);//
+disp(po*10^6,"average power incident in micro Watts is")
diff --git a/2183/CH8/EX8.14.a/Ex_8_14_a.sce b/2183/CH8/EX8.14.a/Ex_8_14_a.sce
new file mode 100755
index 000000000..2715dc19f
--- /dev/null
+++ b/2183/CH8/EX8.14.a/Ex_8_14_a.sce
@@ -0,0 +1,19 @@
+// Example 8.14.a //optical power budget
+clc;
+clear;
+close;
+mip=-10;//dBm
+mop=-25;//dBm
+tsm=mip-mop;//dB
+disp(tsm,"total system margin in dB is")
+l=2;//km
+fcl=3.2;//dB
+lfc=l*fcl;//fiber cable loss in dB
+sl=0.8;//dBm
+slc=sl*l;//dB
+cl=1.6;//dB
+sm=4;//dB
+tsm1=lfc+slc+cl+sm;//dB
+disp(tsm1,"total system margin in dB is")
+epm=tsm-tsm1;//dB
+disp(epm,"excess power margin in dB is")
diff --git a/2183/CH8/EX8.14.b/Ex_8_14_b.sce b/2183/CH8/EX8.14.b/Ex_8_14_b.sce
new file mode 100755
index 000000000..2d421afae
--- /dev/null
+++ b/2183/CH8/EX8.14.b/Ex_8_14_b.sce
@@ -0,0 +1,22 @@
+// Example 8.14.b //possible increase in link length
+clc;
+clear;
+close;
+mip=-10;//dBm
+mop=-25;//dBm
+tsm=mip-mop;//dB
+disp(tsm,"total system margin in dB is")
+l=2;//km
+fcl=3.2;//dB
+lfc=l*fcl;//fiber cable loss in dB
+sl=0.8;//dBm
+slc=sl*l;//dB
+cl=1.6;//dB
+sm=4;//dB
+tsm1=lfc+slc+cl+sm;//dB
+disp(tsm1,"total system margin in dB is")
+epm=tsm-tsm1;//dB
+ma=8;//dB
+l1=((-mop-cl-ma)/(fcl+sl));//km
+eil=l1-l;//
+disp(eil,"possible increase in length in km")
diff --git a/2183/CH8/EX8.15/Ex_8_15.sce b/2183/CH8/EX8.15/Ex_8_15.sce
new file mode 100755
index 000000000..0e86d3b7a
--- /dev/null
+++ b/2183/CH8/EX8.15/Ex_8_15.sce
@@ -0,0 +1,18 @@
+//Example 8.15 // 
+clc;
+clear;
+close;
+//given data :
+B=5*10^6;// in Hz
+Ts=10;// in ns
+Td=4;// in ns
+a=9;// in ns/km
+b=2;// in ns/km
+l=6;// in km
+Tn=a*l;// in ns
+Tc=b*l;// in ns
+Ts_max=(0.35/B)*10^9;
+disp(Ts_max,"T system_maxmum,(ns) = ")
+Tsys=1.1*sqrt(Ts^2+Tn^2+Tc^2+Td^2);
+disp(Tsys,"T system,(ns) = ")
+//answer is wrong in the textbook
diff --git a/2183/CH8/EX8.16.b/Ex_8_16_b.sce b/2183/CH8/EX8.16.b/Ex_8_16_b.sce
new file mode 100755
index 000000000..8c1f952cb
--- /dev/null
+++ b/2183/CH8/EX8.16.b/Ex_8_16_b.sce
@@ -0,0 +1,11 @@
+// Example 8.16.b //SNR improvement and bandwidth
+clc;
+clear;
+close;
+fd=400;//KHz
+ba=4;//kHz
+df1=fd/ba;//
+snri=(1.76+20*log10(df1));//dB
+disp(snri,"SNR improvement in dB is")
+bm=2*ba*(df1+1);//kHz
+disp(bm,"bandwidth in kHz is")
diff --git a/2183/CH8/EX8.17/Ex_8_17.sce b/2183/CH8/EX8.17/Ex_8_17.sce
new file mode 100755
index 000000000..61102e90a
--- /dev/null
+++ b/2183/CH8/EX8.17/Ex_8_17.sce
@@ -0,0 +1,15 @@
+// Example 8.17;//ration of SNR
+clc;
+clear;
+close;
+fa=1;//
+pa=1;//
+r=1;//
+po=1;//
+ac=1;//
+ba=1;//
+no=1;//
+snr1=((3*fa^3*po*(r*po)^2*((ac^2)/2))/(2*ba^3*no));//SNR output FM
+snr2=((fa^3*po*(r*po)^2*((ac^2)/2))/(2*ba^3*no));//SNR output FM
+rt=snr1/snr2;//
+disp(rt,"ratio of output SNR (in dB) in two system is")
diff --git a/2183/CH8/EX8.18/Ex_8_18.sce b/2183/CH8/EX8.18/Ex_8_18.sce
new file mode 100755
index 000000000..a432131cc
--- /dev/null
+++ b/2183/CH8/EX8.18/Ex_8_18.sce
@@ -0,0 +1,17 @@
+//Example 8.18 // Optimum receiver bandwidth and peak to peak signal power to noise ratio
+clc;
+clear;
+close;
+//given data :
+Tr=12*10^-9;// in sec
+f0=20*10^6;// in Hz
+fD=5*10^6;// in Hz
+Mr=80;// multiplication factor
+Pp=.75*10^-7;
+B=5*10^6;// in Hz
+i2N=10^-17;// in A^2
+fr=(1/Tr)*10^-6;
+disp(fr," Optimum receiver bandwidth,fr(MHz) = ")
+T0=1/f0;
+SbyN=10*log10((3*(T0*fD*Mr*Pp)^2)/((2*%pi*Tr*B)^2*i2N));
+disp(SbyN,"signal power to noise ratio,(dB) = ")
diff --git a/2183/CH8/EX8.19/ex_8_19.sce b/2183/CH8/EX8.19/ex_8_19.sce
new file mode 100755
index 000000000..ad3cc6beb
--- /dev/null
+++ b/2183/CH8/EX8.19/ex_8_19.sce
@@ -0,0 +1,16 @@
+// Example 8.19:compare
+clc;
+clear;
+close;
+cl=1;//dB
+actr=10;//dB
+acl=1;//dB
+fcl=4.5;//dB/km
+sl=2.5;//dB
+cel=2;//dB
+dl=100;//m
+x=cel*cl-fcl*dl*10^-3+(cel*cl+cl)*-(cel+cl)+(cel*cl+actr)+sl+cl;//
+x1=(fcl*dl*10^-3)+(cel*cl+cl);//
+disp("total loss for bus distribution system is "+string(x1)+"N + "+string(x)+"")
+x3=(cel*2*cl)+cel+(fcl*dl*10^-3);//
+disp("total loss for star distribution system is "+string(x3)+"+ 10log10(N)")
diff --git a/2183/CH8/EX8.2.a/Ex_8_2_a.sce b/2183/CH8/EX8.2.a/Ex_8_2_a.sce
new file mode 100755
index 000000000..56b90a13b
--- /dev/null
+++ b/2183/CH8/EX8.2.a/Ex_8_2_a.sce
@@ -0,0 +1,7 @@
+// Example 8.2.a //threshold quantum limit

+clc;

+clear;

+close;

+en=10^-9;//

+n=-log(en);//

+disp(round(n),"quantum limit is (photons per pulse required )")

diff --git a/2183/CH8/EX8.2.b/Ex_8_2_b.sce b/2183/CH8/EX8.2.b/Ex_8_2_b.sce
new file mode 100755
index 000000000..7749940ee
--- /dev/null
+++ b/2183/CH8/EX8.2.b/Ex_8_2_b.sce
@@ -0,0 +1,16 @@
+// Example 8.2.b //minumum incident optical power
+clc;
+clear;
+close;
+en=10^-9;
+n=-log(en);//
+c=3*10^8;//m/s
+ht=6.62*10^-34;//plank constt.
+B=10^7;//NO. OF BITS
+h=0.85*10^-6;//wavelength in meter
+Po=((20.7*ht*B*c)/(2*h));//pulse energy in pico Watt
+Podb=10*(log10(Po));//pulse energy in dB when refrence level is one Watt
+Podb1=10*(log10(Po*10^3));//pulse energy in dB when refrence level is one mili Watt
+disp(Po, "minimum incident optical power in Watts is")
+disp(Podb1 , "pulse energy in dB when refrence level is one miiliwatt in dBm")
+
diff --git a/2183/CH8/EX8.20/Ex_8_20.sce b/2183/CH8/EX8.20/Ex_8_20.sce
new file mode 100755
index 000000000..62908f204
--- /dev/null
+++ b/2183/CH8/EX8.20/Ex_8_20.sce
@@ -0,0 +1,17 @@
+// Example 8.20;//maximum length of the system
+clc;
+clear;
+close;
+af=0.20;//dB/km
+ac1=0.05;//dB/km
+k=4;//
+b=1.2;//G bit/s
+c=3*10^8;//m/s
+h=1.55;//micro meter
+sndb=17
+sn=10^(sndb/10);//
+l=100;//km
+hc=6.63*10^-34;//
+lt=((10^-3*h*10^-6*(10^-((af+ac1)*(l/10)))*l*10^3)/(k*hc*c*b*10^12*sn));//
+disp(lt,"maximum length of the system in km is")
+//answer is wrong in the textbook
diff --git a/2183/CH8/EX8.3.a/Ex_8_3_a.sce b/2183/CH8/EX8.3.a/Ex_8_3_a.sce
new file mode 100755
index 000000000..a685518fd
--- /dev/null
+++ b/2183/CH8/EX8.3.a/Ex_8_3_a.sce
@@ -0,0 +1,10 @@
+// Example 8.3.a;//bit rate for the system
+clc;
+clear;
+close;
+wd=8;//bit wide
+ts=32;//time slots
+nb=ts*wd;//no. of bits in a frame
+nf=8*10^3;//no. of frames
+tr=nf*nb;//transmission rate
+disp(tr*10^-6,"transmission rate for the system in M-bits-s^-1")
diff --git a/2183/CH8/EX8.3.b/Ex_8_3_b.sce b/2183/CH8/EX8.3.b/Ex_8_3_b.sce
new file mode 100755
index 000000000..55bbdb025
--- /dev/null
+++ b/2183/CH8/EX8.3.b/Ex_8_3_b.sce
@@ -0,0 +1,12 @@
+// Example 8.3.b //duration of time slot
+clc;
+clear;
+close;
+wd=8;//bit wide
+ts=32;//time slots
+nb=ts*wd;//no. of bits in a frame
+nf=8*10^3;//no. of frames
+tr=nf*nb;//transmission rate
+bdr1=1/tr;//bit duration
+bdr=bdr1*wd;//
+disp(bdr*10^6,"duration of time slot in micro seconds")
diff --git a/2183/CH8/EX8.3.c/Ex_8_3_c.sce b/2183/CH8/EX8.3.c/Ex_8_3_c.sce
new file mode 100755
index 000000000..1d5c65582
--- /dev/null
+++ b/2183/CH8/EX8.3.c/Ex_8_3_c.sce
@@ -0,0 +1,15 @@
+// Example 8.3.c //duration of a frame and multiframe
+clc;
+clear;
+close;
+wd=8;//bit wide
+ts=32;//time slots
+nb=ts*wd;//no. of bits in a frame
+nf=8*10^3;//no. of frames
+tr=nf*nb;//transmission rate
+bdr1=1/tr;//bit duration
+bdr=bdr1*wd;//
+df=bdr*10^6*ts;//duration of frame
+dmf=df*(ts/2);//ms
+disp(df,"duration of frame in micro seconds")
+disp(dmf*10^-3,"duration of multiframe in milli seconds")
diff --git a/2183/CH8/EX8.4/Ex_8_4.sce b/2183/CH8/EX8.4/Ex_8_4.sce
new file mode 100755
index 000000000..4d92ca666
--- /dev/null
+++ b/2183/CH8/EX8.4/Ex_8_4.sce
@@ -0,0 +1,15 @@
+//Example 8.4 // Average nummber of photon
+clc;
+clear;
+close;
+//given data :
+format('v',5)
+M=80;// multiplication factor
+K=0.02;// carrier ionization rates
+eta=85/100;// quntum efficiency
+Bt=0.6;// assuming a raised cosine signal spectrum
+SbyN=144;
+FM=(K*M)+(2-(1/M))*(1-K);
+eta_max=(2*Bt*FM*SbyN)/(eta);
+disp(eta_max,"The average number of photon,(photon) = ")
+// answer is wrong in a textbook
diff --git a/2183/CH8/EX8.5/Ex_8_5.sce b/2183/CH8/EX8.5/Ex_8_5.sce
new file mode 100755
index 000000000..e3d70c069
--- /dev/null
+++ b/2183/CH8/EX8.5/Ex_8_5.sce
@@ -0,0 +1,20 @@
+// Example 8.5;//minumum incident optical power
+clc;
+clear;
+close;
+nmax=732;//
+c=3*10^8;//m/s
+ht=6.62*10^-34;//plank constt.
+B=10^7;//NO. OF BITS
+h=1*10^-6;//wavelength in meter
+Po=((nmax*ht*B*c)/(2*h))*10^12;//pulse energy in pico Watt
+Podb=10*(log10(Po));//pulse energy in dB when refrence level is one Watt
+Podb1=10*(log10(Po*10^-9));//pulse energy in dB when refrence level is one mili Watt
+disp(Podb1 , "pulse energy at bit rate of 10 M bit s^-1 in dBm")
+B1=14*10^7;//NO. OF BITS
+Po1=((nmax*ht*B1*c)/(2*h))*10^12;//pulse energy in pico Watt
+Podb1=10*(log10(Po1));//pulse energy in dB when refrence level is one Watt
+Podb2=10*(log10(Po1*10^-9));//pulse energy in dB when refrence level is one mili Watt
+disp(Podb2 , "pulse energy at bit rate of 140 M bit s^-1 in dBm")
+//at 10 M bit s^-1 power is calc ulated wrong in the book
+
diff --git a/2183/CH8/EX8.6/Ex_8_6.sce b/2183/CH8/EX8.6/Ex_8_6.sce
new file mode 100755
index 000000000..9276eb498
--- /dev/null
+++ b/2183/CH8/EX8.6/Ex_8_6.sce
@@ -0,0 +1,11 @@
+// Example 8.6;//total channel loss
+clc;
+clear;
+close;
+afc=5;//attenuation in dB/km
+aj=2;//splice loss in dB/km
+l=5;//length in km
+ac=3;//dB
+ac1=4.5;//dB
+cl=(afc+aj)*l+ac+ac1;//dB
+disp(cl,"tota channel loss in dB is")
diff --git a/2183/CH8/EX8.7.a/Ex_8_7_a.sce b/2183/CH8/EX8.7.a/Ex_8_7_a.sce
new file mode 100755
index 000000000..c90b9b002
--- /dev/null
+++ b/2183/CH8/EX8.7.a/Ex_8_7_a.sce
@@ -0,0 +1,14 @@
+// Example 8.7.a //dispersion equalization penalty
+clc;
+clear;
+close;
+sg=0.65;// ns km^-1
+l=8;//km
+st=sg*l;//ns
+bt=20;//M bit s^-1
+dlw=2*(2*st*10^-9*bt*10^6*sqrt(2))^4;//dB
+st1=sg*sqrt(l);//ns
+dlw1=2*(2*st1*10^-9*bt*10^6*sqrt(2))^4;//dB
+disp(dlw,"dispersion equalization penalty in dB without mode coupling at bit rate of 20 M bit s^-1")
+disp(dlw1,"dispersion equalization penalty in dB with mode coupling at bit rate of 20 M bit s^-1")
+//penalty with mode coupling is calculated wrong in the book
diff --git a/2183/CH8/EX8.7.b/Ex_8_7_b.sce b/2183/CH8/EX8.7.b/Ex_8_7_b.sce
new file mode 100755
index 000000000..95eb1d982
--- /dev/null
+++ b/2183/CH8/EX8.7.b/Ex_8_7_b.sce
@@ -0,0 +1,14 @@
+// Example 8.7.b;//dispersion equalization penalty
+clc;
+clear;
+close;
+sg=0.65;// ns km^-1
+l=8;//km
+st=sg*l;//ns
+bt=140;//M bit s^-1
+dlw=2*(2*st*10^-9*bt*10^6*sqrt(2))^4;//dB
+st1=sg*sqrt(l);//ns
+dlw1=2*(2*st1*10^-9*bt*10^6*sqrt(2))^4;//dB
+disp(dlw,"dispersion equalization penalty in dB without mode coupling at bit rate of 20 M bit s^-1")
+disp(dlw1,"dispersion equalization penalty in dB with mode coupling at bit rate of 20 M bit s^-1")
+//answer is calculated wrong in the book
diff --git a/2183/CH8/EX8.8/Ex_8_8.sce b/2183/CH8/EX8.8/Ex_8_8.sce
new file mode 100755
index 000000000..9256c65de
--- /dev/null
+++ b/2183/CH8/EX8.8/Ex_8_8.sce
@@ -0,0 +1,16 @@
+
+// Example 8.8 //bit rate
+clc;
+clear;
+close;
+ts=8;//ns
+l=8;//km
+tn=4;//ns
+tn1=tn*l;//ns
+tc=1;//
+tc1=tc*l;//ns
+td=5;//ns
+tsys=1.1*sqrt(ts^2+tn1^2+tc1^2+td^2);//ns
+btmax=(0.7/(tsys*10^-9))*10^-6;//M bit/s
+bt=btmax/2;//
+disp(bt,"maximum bit rate for NRZ format in MHz")
diff --git a/2183/CH8/EX8.9.a/Ex_8_9_a.sce b/2183/CH8/EX8.9.a/Ex_8_9_a.sce
new file mode 100755
index 000000000..3e67f5df5
--- /dev/null
+++ b/2183/CH8/EX8.9.a/Ex_8_9_a.sce
@@ -0,0 +1,12 @@
+// Example 8.9.a //Link length
+clc;
+clear;
+close;
+pi=-3;//dBm
+po=-56;//dBm
+ac=2;//dBm
+ma=8;//dBm
+afc=0.4;//dBm
+aj=0.1;//dBm
+l=((pi-po-ac-ma)/(afc+aj));//km
+disp(l,"link length when operating at 50 M bit/s in km is")
diff --git a/2183/CH8/EX8.9.b/Ex_8_9_b.sce b/2183/CH8/EX8.9.b/Ex_8_9_b.sce
new file mode 100755
index 000000000..663ba9c8b
--- /dev/null
+++ b/2183/CH8/EX8.9.b/Ex_8_9_b.sce
@@ -0,0 +1,12 @@
+// Example 8.9.b;//Link length
+clc;
+clear;
+close;
+pi=-3;//dBm
+po=-42;//dBm
+ac=2;//dBm
+ma=8;//dBm
+afc=0.4;//dBm
+aj=0.1;//dBm
+l=((pi-po-ac-ma)/(afc+aj));//km
+disp(l,"link length when operating at 500 M bit/s in km is")
diff --git a/2183/CH8/EX8.9.c/Ex_8_9_c.sce b/2183/CH8/EX8.9.c/Ex_8_9_c.sce
new file mode 100755
index 000000000..0644ec5e8
--- /dev/null
+++ b/2183/CH8/EX8.9.c/Ex_8_9_c.sce
@@ -0,0 +1,13 @@
+// Example 8.9.c;//Link length
+clc;
+clear;
+close;
+pi=-3;//dBm
+po=-42;//dBm
+ac=2;//dBm
+ma=8;//dBm
+afc=0.4;//dBm
+aj=0.1;//dBm
+dl=1.5;//dbm
+l=((pi-po-ac-ma-dl)/(afc+aj));//km
+disp(l,"link length when dispersion equalisation penalty is included in km is")
diff --git a/2183/CH9/EX9.1/Ex_9_1.sce b/2183/CH9/EX9.1/Ex_9_1.sce
new file mode 100755
index 000000000..82edba842
--- /dev/null
+++ b/2183/CH9/EX9.1/Ex_9_1.sce
@@ -0,0 +1,9 @@
+// Example 9.1;//maximum termperature change

+clc;

+clear;

+close;

+f=0.15;//GHz

+fc=18;//GHz/degree celsius

+ta=f/fc;//

+disp(ta,"maximum temperature change alowed in degree celsius is")

+

diff --git a/2183/CH9/EX9.2/Ex_9_2.sce b/2183/CH9/EX9.2/Ex_9_2.sce
new file mode 100755
index 000000000..150bf973d
--- /dev/null
+++ b/2183/CH9/EX9.2/Ex_9_2.sce
@@ -0,0 +1,15 @@
+// Example 9.2;//bandwidth
+clc;
+clear;
+close;
+snl=-55.45;//dBm
+ps=10^(snl/10);//
+n=0.8;//
+h=1.54;//micro meter
+hc=6.63*10^-34;//
+c=3*10^8;//m/s
+sndb=12;//
+sn=10^(sndb/10);//
+b=((n*ps*10^-3*h*10^-6)/(hc*c*sn));//
+disp(b*10^-9,"bandwidth in GHz is")
+//answer is wrong in the textbook
diff --git a/2183/CH9/EX9.3/Ex_9_3.sce b/2183/CH9/EX9.3/Ex_9_3.sce
new file mode 100755
index 000000000..ab0f6f175
--- /dev/null
+++ b/2183/CH9/EX9.3/Ex_9_3.sce
@@ -0,0 +1,12 @@
+// Example 9.3;//number of received photos
+clc;
+clear;
+close;
+ber=10^-9;//
+x=-2*log10(ber);//
+np1=4*x;//no. of received photons for ASK heterodyne sysnchronous detection
+np2=-4*log(2*ber);//no. of received photons for ASK heterodyne non-sysnchronous detection
+np3=x/2;//no. of received photons for PSK homodyne detection
+disp(round(np1),"no. of received photons for ASK heterodyne sysnchronous detection")
+disp(round(np2),"no. of received photons for ASK heterodyne non-sysnchronous detection")
+disp(round(np3),"no. of received photons for PSK homodyne detection")
diff --git a/2183/CH9/EX9.4/Ex_9_4.sce b/2183/CH9/EX9.4/Ex_9_4.sce
new file mode 100755
index 000000000..81814be17
--- /dev/null
+++ b/2183/CH9/EX9.4/Ex_9_4.sce
@@ -0,0 +1,12 @@
+// Example 9.4 //minimum incoming power level
+clc;
+clear;
+close;
+ber=10^-9;//
+x=-2*log10(ber);//
+hc=6.63*10^-34;//
+c=3*10^8;//m/s
+bt=500;//Mbits/s
+h=1.55;//micro meter
+ps=((x*2*hc*c*bt*10^6)/(h*10^-6));//nW
+disp(ps*10^9,"minimum incoming power level in nano Watts is")
diff --git a/2183/CH9/EX9.5.a/Ex_9_5_a.sce b/2183/CH9/EX9.5.a/Ex_9_5_a.sce
new file mode 100755
index 000000000..3ef3839be
--- /dev/null
+++ b/2183/CH9/EX9.5.a/Ex_9_5_a.sce
@@ -0,0 +1,25 @@
+// Example 9.5.a;//maximum repeater spacing 
+clc;
+clear;
+close;
+ber=10^-9;//
+x1=-2*log10(ber);//
+hc=6.63*10^-34;//
+c=3*10^8;//m/s
+bt=50;//Mbits/s
+h=1.55;//micro meter
+ps=((x1*2*hc*c*bt*10^6)/(h*10^-6));//nW
+psdb=10*log10(ps*10^3);//
+cl=0.25;//dB/km
+x=4;//dBm
+y=x-psdb;//
+mrs1=y/cl;//km
+disp(mrs1,"maximum repeater spacing in km at 50 M-bit/s  system (ASK) in km is")
+bt1=1;//Gbit/s
+ps1=((x1*2*hc*c*bt1*10^9)/(h*10^-6));//nW
+psdb1=10*log10(ps1*10^3);//
+cl=0.25;//dB/km
+x=4;//dBm
+y1=x-psdb1;//
+mrs2=y1/cl;//km
+disp(mrs2,"maximum repeater spacing in km at 1 G-bit/s  system (ASK) in km is")
diff --git a/2183/CH9/EX9.5.b/Ex_9_5_b.sce b/2183/CH9/EX9.5.b/Ex_9_5_b.sce
new file mode 100755
index 000000000..e22050452
--- /dev/null
+++ b/2183/CH9/EX9.5.b/Ex_9_5_b.sce
@@ -0,0 +1,26 @@
+// Example 9.5.B;//maximum repeater spacing 
+clc;
+clear;
+close;
+ber=10^-9;//
+x1=-2*log10(ber);//
+hc=6.63*10^-34;//
+c=3*10^8;//m/s
+bt=50;//Mbits/s
+h=1.55;//micro meter
+ps=(((x1/2)*hc*c*bt*10^6)/(h*10^-6));//nW
+psdb=10*log10(ps*10^3);//
+cl=0.25;//dB/km
+x=4;//dBm
+y=x-psdb;//
+mrs1=y/cl;//km
+disp(mrs1,"maximum repeater spacing in km at 50 M-bit/s  system (PSK) in km is")
+bt1=1;//Gbit/s
+ps1=(((x1/2)*2*hc*c*bt1*10^9)/(h*10^-6));//nW
+psdb1=10*log10(ps1*10^3);//
+cl=0.25;//dB/km
+x=4;//dBm
+y1=x-psdb1;//
+mrs2=y1/cl;//km
+disp(mrs2,"maximum repeater spacing in km at 1 G-bit/s  system (PSK) in km is")
+//for 1 Gbit/s systme answer is wrong in the textbook
diff --git a/2183/CH9/EX9.6/Ex_9_6.sce b/2183/CH9/EX9.6/Ex_9_6.sce
new file mode 100755
index 000000000..108c73b98
--- /dev/null
+++ b/2183/CH9/EX9.6/Ex_9_6.sce
@@ -0,0 +1,17 @@
+//Example 9.6 // refractive index and 3dB spectral bandwidth
+clc;
+clear;
+close;
+//given data :
+lamda=1.5*10^-6;// in m
+L=300*10^-6;// in m
+del_lamda=10^-9;// in m
+n=lamda^2/(2*del_lamda*L);
+disp(n,"refractive index , n = ")
+R1=0.3;
+R2=R1;
+a=4.8;// in dB
+Gs=10^(4.8/10);
+c=3*10^8;
+B=(c/(%pi*n*L)*asin((1-sqrt(R1*R2)*Gs)/(2*sqrt(sqrt(R1*R2)*Gs))))*10^-9;
+disp(B," Spectral bandwidth,(GHz) = ")
diff --git a/2183/CH9/EX9.7/Ex_9_7.sce b/2183/CH9/EX9.7/Ex_9_7.sce
new file mode 100755
index 000000000..9650a1ba7
--- /dev/null
+++ b/2183/CH9/EX9.7/Ex_9_7.sce
@@ -0,0 +1,8 @@
+//Example 9.7// cavity gain
+clc;
+clear;
+close;
+x=0.5;//
+y=(1-(sqrt(x)))/(1+sqrt(x));//
+g=(y/(1-y)^2);//
+disp("cavity gain is "+string(g)+"/(sqrt(R1*R2))")