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 "worksheets": [

  {

   "cells": [

    {

     "cell_type": "heading",

     "level": 1,

     "metadata": {},

     "source": [

      "Chapter03:Optical Sources and Transmitters"

     ]

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.2.1:Pg-3.10"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "x= 0.07 \n",

      "Eg= 1.424+1.266*x+0.266*x**2 \n",

      "lamda= 1.24/Eg \n",

      "print \" The emitted wavelength in um =\",round(lamda,2) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The emitted wavelength in um = 0.82\n"

       ]

      }

     ],

     "prompt_number": 6

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.2.2:Pg-3.10"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "x= 0.26 \n",

      "y=0.57 \n",

      "Eg= 1.35-0.72*y+0.12*y**2 \n",

      "lamda = 1.24/Eg \n",

      "print \" The wavelength emitted in um =\",round(lamda,2) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The wavelength emitted in um = 1.27\n"

       ]

      }

     ],

     "prompt_number": 7

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.2.3:Pg-3.12"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "\n",

      "Tr = 60*10**-9    # radiative recombination time\n",

      "Tnr= 90*10**-9    # non radiative recomb time\n",

      "I= 40*10**-3      # current\n",

      "t = Tr*Tnr/(Tr+Tnr)      # total recomb time\n",

      "t=t*10**9     # Converting in nano secs...\n",

      "print \" The total carrier recombination life time in ns =\",int(t) \n",

      "t=t/10**9 \n",

      "h= 6.625*10**-34      # plancks const\n",

      "c= 3*10**8 \n",

      "q=1.602*10**-19 \n",

      "lamda= 0.87*10**-6 \n",

      "Pint=(t/Tr)*((h*c*I)/(q*lamda)) \n",

      "Pint=Pint*1000   # converting inmW...\n",

      "print \" \\n\\nThe Internal optical power in mW =\",round(Pint,2) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The total carrier recombination life time in ns = 36\n",

        " \n",

        "\n",

        "The Internal optical power in mW = 34.22\n"

       ]

      }

     ],

     "prompt_number": 8

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.2.4:Pg-3.13"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "lamda = 1310*10**-9 \n",

      "Tr= 30*10**-9 \n",

      "Tnr= 100*10**-9 \n",

      "I= 40*10**-3 \n",

      "t= Tr*Tnr/(Tr+Tnr) \n",

      "t=t*10**9    # converting in nano secs...\n",

      "print \" Bulk recombination life time in ns =\",round(t,2) \n",

      "t=t/10**9 \n",

      "n= t/Tr \n",

      "print \" \\n\\nInternal quantum efficiency =\",round(n,3) \n",

      "h= 6.625*10**-34      # plancks const\n",

      "c= 3*10**8 \n",

      "q=1.602*10**-19 \n",

      "Pint=(0.769*h*c*I)/(q*lamda)*1000 \n",

      "print \" \\n\\nThe internal power level in mW =\",round(Pint,3) \n",

      "print \" \\n\\n***NOTE: Internal Power wrong in text book.. Calculation Error..\" \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " Bulk recombination life time in ns = 23.08\n",

        " \n",

        "\n",

        "Internal quantum efficiency = 0.769\n",

        " \n",

        "\n",

        "The internal power level in mW = 29.131\n",

        " \n",

        "\n",

        "***NOTE: Internal Power wrong in text book.. Calculation Error..\n"

       ]

      }

     ],

     "prompt_number": 9

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.2.5:Pg-3.14"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "nx= 3.6 \n",

      "TF= 0.68 \n",

      "n= 0.3 \n",

      " # Pe=Pint*TF*1/(4*nx**2) \n",

      " # ne= Pe/Px*100     ..eq0\n",

      " # Pe = 0.013*Pint      # Eq 1\n",

      " # Pint = n*P     # Eq 2\n",

      " # substitute eq2 and eq1 in eq0\n",

      "ne = 0.013*0.3*100 \n",

      "print \" The external Power efficiency in % =\",round(ne,3) \n",

      " #  Wrongly printed in textbook. it should be P instead of Pint in last step\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The external Power efficiency in % = 0.39\n"

       ]

      }

     ],

     "prompt_number": 11

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.2.6:Pg-3.15"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "\n",

      "lamda= 0.85*10**-6 \n",

      "Nint = 0.60 \n",

      "I= 20*10**-3 \n",

      "h= 6.625*10**-34      # plancks const\n",

      "c= 3*10**8 \n",

      "e=1.602*10**-19 \n",

      "Pint = Nint*h*c*I/(e*lamda) \n",

      "print \" The optical power emitted in W =\",round(Pint,4) \n",

      "\n",

      "TF= 0.68 \n",

      "nx= 3.6 \n",

      "Pe= Pint*TF/(4*nx**2)*1000000 \n",

      "print \" \\n\\nPower emitted in the air in uW =\",round(Pe,1) \n",

      "Pe=Pe/1000000 \n",

      "Nep=Pe/Pint*100 \n",

      "print \" \\n\\nExternal power efficiency in % =\",round(Nep,1) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The optical power emitted in W = 0.0175\n",

        " \n",

        "\n",

        "Power emitted in the air in uW = 229.7\n",

        " \n",

        "\n",

        "External power efficiency in % = 1.3\n"

       ]

      }

     ],

     "prompt_number": 12

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.2.7:Pg-3.16"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "\n",

      "lamda = 0.87*10**-6 \n",

      "Tr= 50*10**-9 \n",

      "I= 0.04 \n",

      "Tnr= 110*10**-9 \n",

      "t= Tr*Tnr/(Tr+Tnr) \n",

      "t=t*10**9    # converting in ns...\n",

      "print \" Total carrier recombination life time in ns =\",round(t,2) \n",

      "t=t/10**9 \n",

      "h= 6.625*10**-34      # plancks const\n",

      "c= 3*10**8 \n",

      "q=1.602*10**-19 \n",

      "n= t/Tr \n",

      "print \" \\n\\nThe efficiency in % \",round(n,3) \n",

      "Pint=(n*h*c*I)/(q*lamda)*1000 \n",

      "print \" \\n\\nInternal power generated in mW =\",round(Pint,2) \n",

      "print \" \\n\\n***NOTE- Internal Power wrong in book... \"\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " Total carrier recombination life time in ns = 34.38\n",

        " \n",

        "\n",

        "The efficiency in %  0.688\n",

        " \n",

        "\n",

        "Internal power generated in mW = 39.22\n",

        " \n",

        "\n",

        "***NOTE- Internal Power wrong in book... \n"

       ]

      }

     ],

     "prompt_number": 15

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.2.8:Pg-3.16"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      " \n",

      "\n",

      "V= 2 \n",

      "I= 100*10**-3 \n",

      "Pc= 2*10**-3 \n",

      "P= V*I \n",

      "Npc= Pc/P*100 \n",

      "print \" The overall power conversion efficiency in % =\",int(Npc) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The overall power conversion efficiency in % = 1\n"

       ]

      }

     ],

     "prompt_number": 16

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.3.1:Pg-3.25"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "import math\n",

      "\n",

      "r1= 0.32 \n",

      "r2= 0.32 \n",

      "alpha= 10 \n",

      "L= 500*10**-4 \n",

      "temp=math.log(1/(r1*r2)) \n",

      "Tgth = alpha + (temp/(2*L)) \n",

      "print \" The optical gain at threshold in /cm =\",round(Tgth,2) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The optical gain at threshold in /cm = 32.79\n"

       ]

      }

     ],

     "prompt_number": 17

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.3.2:Pg-3.27"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      " \n",

      "n= 3.7 \n",

      "lamda = 950*10**-9 \n",

      "L= 500*10**-6 \n",

      "c= 3*10**8 \n",

      "DELv = c/(2*L*n)*10*10**-10   # converting in GHz...\n",

      "print \" The frequency spacing in GHz =\",int(DELv) \n",

      "DEL_lamda= lamda**2/(2*L*n)*10**9   # converting to nm..\n",

      "print \" \\n\\nThe wavelength spacing in nm =\",round(DEL_lamda,2) \n",

      "\n",

      "print \" \\n\\n***NOTE- The value of wavelength taken wrongly in book\" \n",

      " #  value of lamda taken wrongly while soving for DEL_LAMDA inthe book..\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The frequency spacing in GHz = 81\n",

        " \n",

        "\n",

        "The wavelength spacing in nm = 0.24\n",

        " \n",

        "\n",

        "***NOTE- The value of wavelength taken wrongly in book\n"

       ]

      }

     ],

     "prompt_number": 18

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.3.3:Pg-3.30"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      " #Given\n",

      " \n",

      "L= 0.04 \n",

      "n= 1.78 \n",

      "lamda= 0.55*10**-6 \n",

      "c= 3*10**8 \n",

      "q= 2*n*L/lamda \n",

      "q=q/10**5 \n",

      "print \" Number of longitudinal modes  =\",round(q,2),\"x 10^5\" \n",

      "del_f= c/(2*n*L) \n",

      "del_f=del_f*10**-9 \n",

      "print \" \\n\\nThe frequency seperation in GHz =\",round(del_f,1) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " Number of longitudinal modes  = 2.59 x 10^5\n",

        " \n",

        "\n",

        "The frequency seperation in GHz = 2.1\n"

       ]

      }

     ],

     "prompt_number": 20

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.3.4:Pg-3.33"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "\n",

      "Nt= 0.18 \n",

      "V= 2.5 \n",

      "Eg= 1.43 \n",

      "Nep= Nt*Eg*100/V \n",

      "print \" The total efficiency in % =\",round(Nep,3) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The total efficiency in % = 10.296\n"

       ]

      }

     ],

     "prompt_number": 22

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.3.5:Pg-3.33"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "\n",

      "n= 3.6 \n",

      "BETA= 21*10**-3 \n",

      "alpha= 10 \n",

      "L= 250*10**-4 \n",

      "\n",

      "r= (n-1)**2/(n+1)**2 \n",

      "Jth= 1/BETA *( alpha + (math.log(1/r)/L)) \n",

      "Jth=Jth/1000   # converting for displaying...\n",

      "print \" The threshold current density =\",round(Jth,3),\"x 10**3\" \n",

      "Jth=Jth*1000 \n",

      "Ith  =Jth*250*100*10**-8 \n",

      "Ith=Ith*1000   # converting into mA...\n",

      "print \" \\n\\nThe threshold current in mA =\",round(Ith,1) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The threshold current density = 2.65 x 10**3\n",

        " \n",

        "\n",

        "The threshold current in mA = 662.4\n"

       ]

      }

     ],

     "prompt_number": 24

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.3.6:Pg-3.34"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "\n",

      "T= 305.0 \n",

      "T0 = 160.0 \n",

      "T1= 373.0\n",

      "\n",

      "Jth_32 = exp(T/T0) \n",

      "Jth_100 = exp(T1/T0) \n",

      "R_j = Jth_100/Jth_32 \n",

      "print \" Ratio of current densities at 160K is =\",round(R_j,2) \n",

      "print \" \\n\\n***NOTE- Wrong in book...\\nJth(100) calculated wrongly...\" \n",

      "To = 55 \n",

      "Jth_32_new = exp(T/To) \n",

      "Jth_100_new = exp(T1/To) \n",

      "R_j_new = Jth_100_new/Jth_32_new \n",

      "print \" \\n\\nRatio of current densities at 55K is  \",round(R_j_new,2) \n",

      " # wrong in book...\n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " Ratio of current densities at 160K is = 1.53\n",

        " \n",

        "\n",

        "***NOTE- Wrong in book...\n",

        "Jth(100) calculated wrongly...\n",

        " \n",

        "\n",

        "Ratio of current densities at 55K is   3.44\n"

       ]

      }

     ],

     "prompt_number": 26

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.4.1:Pg-3.42"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "import math\n",

      "\n",

      "Bo= 150 \n",

      "rs= 35*10**-4 \n",

      "a1= 25*10**-6 \n",

      "NA= 0.20 \n",

      "a2= 50*10**-6 \n",

      "\n",

      "Pled = (a1/rs)**2 * (math.pi**2*rs**2*Bo*NA**2) \n",

      "Pled=Pled*10**10   # converting in uW...\n",

      "print \" The power coupled inthe fibre in uW =\",int(Pled) \n",

      "Pled_new = (math.pi**2*rs**2*Bo*NA**2) \n",

      "Pled_new=Pled_new*10**6   # converting in uW...\n",

      "print \" \\n\\nThe Power coupled for case 2 in uW =\",round(Pled_new,2) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The power coupled inthe fibre in uW = 370\n",

        " \n",

        "\n",

        "The Power coupled for case 2 in uW = 725.42\n"

       ]

      }

     ],

     "prompt_number": 27

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.4.2:Pg-3.43"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "import math\n",

      "n= 1.48 \n",

      "n1= 3.6 \n",

      "R= (n1-n)**2/(n1+n)**2 \n",

      "print \" The Fresnel Reflection is  \",round(R,4) \n",

      "L= -10*math.log10(1-R) \n",

      "print \" \\n\\nPower loss in dB =\",round(L,2) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The Fresnel Reflection is   0.1742\n",

        " \n",

        "\n",

        "Power loss in dB = 0.83\n"

       ]

      }

     ],

     "prompt_number": 28

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.4.3:Pg-3.44"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "import math\n",

      "\n",

      "NA= 0.20 \n",

      "Bo= 150 \n",

      "rs= 35*10**-6 \n",

      "Pled = math.pi**2*rs**2*Bo*NA**2 \n",

      "Pled=Pled*10**10   # convertin in uW for displaying...\n",

      "print \" The optical power coupled in uW =\",round(Pled,2) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The optical power coupled in uW = 725.42\n"

       ]

      }

     ],

     "prompt_number": 29

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.4.4:Pg-3.44"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "import math\n",

      "\n",

      "n1= 1.5 \n",

      "n=1 \n",

      "R= (n1-n)**2/(n1+n)**2 \n",

      "L= -10*math.log10(1-R) \n",

      " # Total loss is twice due to reflection\n",

      "L= L+L \n",

      "print \" Total loss due to Fresnel Reflection in dB =\",round(L,2) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " Total loss due to Fresnel Reflection in dB = 0.35\n"

       ]

      }

     ],

     "prompt_number": 30

    },

    {

     "cell_type": "heading",

     "level": 2,

     "metadata": {},

     "source": [

      "Ex3.4.5:Pg-3.51"

     ]

    },

    {

     "cell_type": "code",

     "collapsed": false,

     "input": [

      "#Given\n",

      "import math\n",

      " \n",

      "n1= 1.5 \n",

      "n=1.0 \n",

      "y=5.0 \n",

      "a= 25.0 \n",

      "temp1=(1-(y/(2*a)**2))**0.5 \n",

      "temp1=temp1*(y/a) \n",

      "temp=2*math.acos(0.9996708)  #  it should be acos(0.1) actually... due to approximations\n",

      "    \n",

      "    #  answer varies a lot... \n",

      "temp=math.degrees(temp)-temp1 \n",

      " # temp=temp \n",

      "tem= 16*(1.5**2)/(2.5**4) \n",

      "tem=tem/math.pi \n",

      "temp=temp*tem \n",

      "Nlat= temp \n",

      "print \" The Coupling efficiency is =\",round(Nlat,3) \n",

      "L= -10*math.log10(Nlat) \n",

      "print \" \\n\\nThe insertion loss in dB =\",round(L,2) \n",

      "temp1=(1-(y/(2*a)**2))**0.5 \n",

      "temp1=temp1*(y/a) \n",

      "temp=2*math.acos(0.9996708)  #  it should be acos(0.1) actually... due to approximations\n",

      "    #  answer varies a lot... \n",

      "temp=math.degrees(temp)-temp1 \n",

      "temp=temp/math.pi \n",

      "N_new =temp  \n",

      "print \" \\n\\nEfficiency when joint index is matched =\",round(N_new,3) \n",

      "L_new= -10*math.log10(N_new) \n",

      "print \" \\n\\nThe new insertion loss in dB =\",round(L_new,2) \n"

     ],

     "language": "python",

     "metadata": {},

     "outputs": [

      {

       "output_type": "stream",

       "stream": "stdout",

       "text": [

        " The Coupling efficiency is = 0.804\n",

        " \n",

        "\n",

        "The insertion loss in dB = 0.95\n",

        " \n",

        "\n",

        "Efficiency when joint index is matched = 0.872\n",

        " \n",

        "\n",

        "The new insertion loss in dB = 0.59\n"

       ]

      }

     ],

     "prompt_number": 39

    }

   ],

   "metadata": {}

  }

 ]

}