{
 "metadata": {
  "name": "",
  "signature": "sha256:1d457d6d35a4d96cef8f5c393fb2ad194f0093b445ed9ceab1c1a00b3a80e8fa"
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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 6: Photodetectors"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.1, Page Number: 224"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "\n",
      "#variable declaration\n",
      "h = 6.625*10**-34                          #planks constant(J*s)\n",
      "C = 3*10**8                                #free space velocity(m/s)\n",
      "Eg = 1.43*1.6*10**-19                      #(joules)\n",
      "\n",
      "#calculation\n",
      "LambdaC = h*C/Eg                           #wavelength(nm)\n",
      "\n",
      "#result\n",
      "print \"Maximum wavelength for photodiode GaAs = \", round(LambdaC*10**9,0),\"nm\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Maximum wavelength for photodiode GaAs =  869.0 nm\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.2, Page Number: 226"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "\n",
      "#variable declaration\n",
      "Ip_q = 5.4*10**6                     #electron-hole pair generated\n",
      "Pin_hv = 6*10**6                     #number of incident photons\n",
      "\n",
      "#calculation\n",
      "etta = Ip_q / Pin_hv                 #Quantum efficiency\n",
      "\n",
      "#result\n",
      "print \"Quantum efficiency at 1300nm =\" ,etta*100,\"%\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Quantum efficiency at 1300nm = 90.0 %\n"
       ]
      }
     ],
     "prompt_number": 8
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.3, Page Number: 226"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "\n",
      "#variable declaration\n",
      "R = 0.65                                  #Responsivity of photodiode(A/W)\n",
      "Pin = 10*10**-6                           #Optical power level(watts)\n",
      "\n",
      "#calculation\n",
      "Ip = R*Pin                                #Photocurrent(A)\n",
      "\n",
      "#result\n",
      "print \"Photocurrent =\",Ip*10**6,\"uA\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Photocurrent = 6.5 uA\n"
       ]
      }
     ],
     "prompt_number": 12
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.4, Page Number: 227"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "\n",
      "#variable declaration\n",
      "Lambda = 1300*10**-9                #Wavelength (m)\n",
      "C = 3*10**8                         #freespace velocity(m/s)\n",
      "q = 1.6*10**-19                     #Charge (coulombs)\n",
      "etta = 0.9                          #Quantum efficiency\n",
      "h = 6.625*10**-34                   #planks constant(J*s)\n",
      "Eg = 0.73                           #energy gap(eV)\n",
      "\n",
      "#calculation\n",
      "R = (etta*q*Lambda)/(h*C)           #responsivity(A/W)\n",
      "LambdaC = 1.24/ Eg                  #cut\udbc0\udc00off wavelength(meters)\n",
      "\n",
      "#result\n",
      "print \"Responsivity = \",round(R,2),\"A/W\"\n",
      "print \"Cutoff wavelength = \",round(LambdaC,1),\"um\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Responsivity =  0.94 A/W\n",
        "Cutoff wavelength =  1.7 um\n"
       ]
      }
     ],
     "prompt_number": 20
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.5, Page Number: 230"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "\n",
      "#variable declaration\n",
      "etta = 0.65                         #Quantum efficiency\n",
      "C = 3*10**8                         #freespace velocity(m/s)\n",
      "Lambda = 900*10**-9                 #Wavelength (m)\n",
      "q = 1.6*10**-19                     #Charge (coulombs)\n",
      "h = 6.625*10**-34                   #planks constant(J*s)\n",
      "Pin = 0.5*10**-06                   #optical power(W)\n",
      "Im = 10*10**-06                     #multiplied photocurrent(uA)\n",
      "\n",
      "#calculation\n",
      "Ip = ((etta*q*Lambda)/(h*C))*Pin    #photocurrent(uA)\n",
      "M = Im/Ip                           #multiplication\n",
      "\n",
      "#result\n",
      "print \"Primary photocurrent = \",round(Ip*10**6,3),\"uA\"\n",
      "print \"Primary photocurrent is multiplied by \" ,round(M+1,0)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Primary photocurrent =  0.235 uA\n",
        "Primary photocurrent is multiplied by  43.0\n"
       ]
      }
     ],
     "prompt_number": 26
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.6, Page Number: 234"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "\n",
      "#variable declaration\n",
      "Lambda = 1330.0*10**-9                  #Wavelength (m)\n",
      "ID = 4.0*10**-9                         #photdiode current(nA)\n",
      "etta = 0.90                             #Quantum efficiency\n",
      "RL = 1000.0                             #load resistance(ohms)\n",
      "Pin = 300.0*10**-9                      #incident optical power(nW)\n",
      "Be = 20.0*10**6                         #reciver bandwidth\n",
      "q = 1.6*10**-19                         #Charge (coulombs)\n",
      "h = 6.625*10**-34                       #planks constant(J*s)\n",
      "T = 283.0                               #room temperature(kelvin)\n",
      "KB = 1.38*10**-23                       #boltzmann's constant\n",
      "\n",
      "#calculation\n",
      "Ip = (etta*q*Pin*1.3*10**-6)/(h*C)        #primary current(uA)\n",
      "Ishot = 2*q*Ip*Be                         #mean-squre shot noise current(A^2)\n",
      "IDB = 2*q*ID*Be                           #mean-squre dark current(A^2)\n",
      "IT = (4*KB*T)*Be/RL                       #mean-sqare thermal current(A^2)\n",
      "\n",
      "#result\n",
      "print \"Primary current = \",round(Ip*10**6,3),\"uA\"\n",
      "print \"Mean-squre shot noise current = \",round(Ishot*10**18,2)*10**-18,\"A^2  OR = \",round(math.sqrt(Ishot)*10**9,2),\"nA\"\n",
      "print \"Mean-squre dark current = \",round(IDB*10**20,2)*10**-20,\"A^2  OR = \",round(math.sqrt(IDB)*10**9,2),\"nA\"\n",
      "print \"Mean-squre thermal current = \",round(math.sqrt(IT)*10**9,0),\"nA\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Primary current =  0.283 uA\n",
        "Mean-squre shot noise current =  1.81e-18 A^2  OR =  1.34 nA\n",
        "Mean-squre dark current =  2.56e-20 A^2  OR =  0.16 nA\n",
        "Mean-squre thermal current =  18.0 nA\n"
       ]
      }
     ],
     "prompt_number": 13
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example 6.7, Page Number: 239"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "import math\n",
      "\n",
      "#variable declaration\n",
      "CP = 3*10**-12                    #photodiode capacitance(pF)\n",
      "CA = 4*10**-12                    #amplifier capacitance(pF)\n",
      "CT = CP+CA                        #total capacitance\n",
      "RT1 = 1000                        #load resistance 1(ohms)\n",
      "RT2 = 50                          #load resistance 2(ohms)\n",
      "\n",
      "#calculation\n",
      "BC1 = 1/(2*math.pi*RT1*CT)        #circuit bandwidth 1 (Hz)\n",
      "BC2 = 1/(2*math.pi*RT2*CT)        #circuit bandwidth 2 (Hz)\n",
      "\n",
      "#result\n",
      "print \"Circuit bandwidth  for 1k ohms = \",round(BC1*10**-6,0),\"MHz\"\n",
      "print \"Circuit bandwidth  for 50 ohms = \",round(BC2*10**-6,0), \"MHz\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Circuit bandwidth  for 1k ohms =  23.0 MHz\n",
        "Circuit bandwidth  for 50 ohms =  455.0 MHz\n"
       ]
      }
     ],
     "prompt_number": 9
    }
   ],
   "metadata": {}
  }
 ]
}