{ "metadata": { "name": "Chapter_8" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": "Chapter - 8 : Optical detectors" }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 8.1, page 454" }, { "cell_type": "code", "collapsed": false, "input": "#Variable declaration\nn=1.2*10**11 #no of electrons\nm=3*10**11 #no of photons\ne=1.602*10**-19 #1 electron volt\nh=0.85*10**-6 #wavelength\nh1=6.626*10**-34 #plancks constant\nc=2.998*10**8 #speed of light\n\n#Calculation\nQ=n/m #quantum efficiency\nR=(Q*e*h)/(h1*c) #responsivity\n\n#Result\nprint'Quantum efficiency = %.1f '%Q\nprint'Responsivity = %.3f A W^-1'%R", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Quantum efficiency = 0.4 \nResponsivity = 0.274 A W^-1\n" } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 8.2, page 454" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nh1=6.626*10**-34 #plancks constant\nc=2.998*10**8 #speed of light\nE=1.5*10**-19 #energy of photons\nn=0.65 #quantum efficiency\ne=1.602*10**-19 #1 electron volt\nio=2.5*10**-6 #photocurrent\n\n#Calculation\nh=h1*c/E #wavelength\nR=(n*e)/(E) #responsivity\npo=io/R #incident optical power\n\n#Result\nprint'(a) Wavelength = %.2f um'%(h*10**6)\nprint'(b) Incident optical power = %.2f uW'%(po*10**6) \n", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "(a) Wavelength = 1.32 um\n(b) Incident optical power = 3.60 uW\n" } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 8.3, page 456" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nh1=6.626*10**-34 #plancks constant\nc=2.998*10**8 #speed of light\ne=1.602*10**-19 #1 electron volt\nE=1.43 #bandgap energy in eV\n\n#Calculation\nh=h1*c/(E*e) #wavelength\n\n#Result\nprint'Wavelength = %.3f um'%(h*10**6)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Wavelength = 0.867 um\n" } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 8.4, page 463" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nw=20*10**-6 #width\nvd=10**5 #drift velocity\nr=500*10**-6 #diameter in meter\nes=10.5*10**-13 #permitivity\n\n#Calculation\ntd=w/vd #drift time\nA=math.pi*r**2 #area\ncj=es*A/w #junction capacitance\n\n#Result\nprint'Drift time = %.1f x 10^-10 S'%(td*10**10)\nprint'Junction capacitance = %.2f x 10^-13 F'%(cj*10**13)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Drift time = 2.0 x 10^-10 S\nJunction capacitance = 0.41 x 10^-13 F\n" } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 8.5, page 464" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nvd=3*10**4 #drift velocity\nw=25*10**-6 #width\n\n#Calculation\nBm=vd/(2*math.pi*w) #maximum bandwidth\ntr=1/Bm #maximum response time\n\n#Result\nprint'Maximum response time = %.1f ns'%(tr*10**9)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Maximum response time = 5.2 ns\n" } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 8.6, page 470" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nh1=6.626*10**-34 #plancks constant\nc=2.998*10**8 #speed of light\ne=1.602*10**-19 #1 electron volt\nl=8*10**-9 #dark current\nn=0.55 #quantum efficiency\nh=1.3*10**-6 #wavelength\nA=100*50*10**-12\n\n#Calculation\nnep=(h1*c*math.sqrt(2*e*l))/(n*e*h) #Noise equivalent power\nD=math.sqrt(A)/nep #Specific detectivity\n\n#Result\nprint'Noise equivalent power = %.2f x 10^-14 W'%(nep*10**14)\nprint'Specific detectivity = %.1f x 10^8 m Hz^(1/2) W^-1'%(D*10**-8)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Noise equivalent power = 8.78 x 10^-14 W\nSpecific detectivity = 8.1 x 10^8 m Hz^(1/2) W^-1\n" } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 8.7, page 482" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nh1=6.626*10**-34 #plancks constant\nc=2.998*10**8 #speed of light\ne=1.602*10**-19 #1 electron volt\nn=0.8 #quantum efficiency\nh=0.9*10**-6 #wavelength\npo=0.5*10**-6 #incident optical power\nI=11*10**-6 #output current\n\n#Calculation\nR=(n*e*h)/(h1*c) #resposivity\nIp=po*R #photocurrent\nM=I/Ip #multiplication factor\n\n#Result\nprint'Multiplication factor = %.2f '%M\n", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Multiplication factor = 37.89 \n" } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 8.8, page 487" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nh1=6.626*10**-34 #plancks constant\nc=2.998*10**8 #speed of light\ne=1.602*10**-19 #1 electron volt\nh=1.26*10**-6 #wavelength\nIc=15*10**-3 #collector current\npo=125*10**-6 #incident optical power\nn=0.4 #quantum efficiency\n\n#Calculation\ngo=(h1*c*Ic)/(h*e*po) #Optical gain\nhfe=go/n #Common emitter current gain\n \n#Result\nprint'Optical gain, Go = %.1f'%go\nprint'Common emitter current gain, hfe = %.1f '%hfe", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Optical gain, Go = 118.1\nCommon emitter current gain, hfe = 295.2 \n" } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 8.9, page 491" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nt=5*10**-12 #electron transit time\nG=70 #Optical gain\n\n#Calculation\nB=1/(2*math.pi*t*G) #Maximum 3dB bandwidth\n\n#Result\nprint'Maximum bandwidth = %.1f MHz'%(B*10**-6)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Maximum bandwidth = 454.7 MHz\n" } ], "prompt_number": 9 } ], "metadata": {} } ] }