{ "metadata": { "name": "Chapter_13" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": "Chapter 13: Optical fiber systems 2: coherent and phase-modulated" }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 13.1, page 832" }, { "cell_type": "code", "collapsed": false, "input": "#Variable declaration\nf1=150*10**6 #reciever IF\nf2=19*10**9 #output frequency change\n\n\n#Calculation\nm=f1*f2**-1 #maximum tempreture change\n\n#Result\nprint'Maximum tempreture change = %d \u00d7 10^-3 \u00b0C '%round(m*10**3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Maximum tempreture change = 8 \u00d7 10^-3 \u00b0C \n" } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 13.2, page 834" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\np=-85.45/10\nn=0.86 #quantum efficiency\nh1=1.54*10**-6 #homodyne receiver operating wavelength\nsn=10**-1.2 #SNR\nh=6.626*10**-34 #plancks constant\nc=2.998*10**8 #velocity of light\n\n\n#Calculation\nps=10**(p) #incoming signal power in dB\nB=(n*ps*sn*h1)/(h*c) #Bandwidth\n\n#Result\nprint'Incoming signal power, Ps = %f nW'%(ps*10**9)\nprint'Operating bandwidth, B = %.1f GHz'%(B*10**-9)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Incoming signal power, Ps = 2.851018 nW\nOperating bandwidth, B = 1.2 GHz\n" } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 13.3, page 878" }, { "cell_type": "code", "collapsed": false, "input": "#Variable declaration\npe=4.24 #probability error function\npe2=20 #probability exponential function\n\n\n#Calculation\nNp=pe**2*4 #no of photons\nNp2=pe2*4\nNp3=pe**2/2\n\n#Result\nprint'(a) ASK heterodyne synchronous detection = %d photons'%round(Np)\nprint'(b) ASK heterodyne asynchronous detection = %d photons'%round(Np2)\nprint'(c) pSK homodyne detection = %d photons'%round(Np3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "(a) ASK heterodyne synchronous detection = 72 photons\n(b) ASK heterodyne asynchronous detection = 80 photons\n(c) pSK homodyne detection = 9 photons\n" } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 13.4, page 881" }, { "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\nBt=400*10**6 #FSK signal bit rate\nh=1.55*10**-6 #wavelength\n\n#Calculation\nps=(36*h1*c*Bt)/(h) #optical power\n\n#Result\nprint'Minimum incoming optical power level = %.1f nW'%(ps*10**9)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Minimum incoming optical power level = 1.8 nW\n" } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 13.5, page 883" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nNp=36 #average photons\nNp2=9 #average photons\nh=6.63*10**-34 #plancks constant\nf=3*10**8 #frequency\nBt=50*10**6 #bit rates\nBt2=10**9 #bit rates\nh1=1.55*10**-6 #operating wavelength\na=0.2 #connector loss\n\n\n#Calculation\nPs=Np*h*f*Bt/h1 #in watt\nPs1=10*math.log10(Ps*10**3) #in dB\nma=4-Ps1 #Max. system margin\nmar=ma/a #Max. repeater spacing \n \nPs2=Np*h*f*Bt2/h1 #in watt\nPs3=10*math.log10(Ps2*10**3) #in dB\nma1=4-Ps3 #Max. system margin\nmar1=ma1/a #Max. repeater spacing \n\nPs4=Np2*h*f*Bt/h1 #in watt\nPs5=10*math.log10(Ps4*10**3) #in dB\nma2=4-Ps5 #Max. system margin\nmar2=ma2/a #Max. repeater spacing \n\nPs6=Np2*h*f*Bt2/h1 #in watt\nPs7=10*math.log10(Ps6*10**3) #in dB\nma3=4-Ps7 #Max. system margin\nmar3=ma3/a #Max. repeater spacing \n\n\n#Result\nprint'(a)Max. repeater spacing (50 Mbit s^-1) = %.1f km'%round(mar)\nprint' (1 Gbit s^-1) = %.1f km'%round(mar1)\nprint'\\n(b)Max. repeater spacing (50 Mbit s^-1) = %.1f km'%round(mar2)\nprint' (1 Gbit s^-1) = %.1f km'%round(mar3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "(a)Max. repeater spacing (50 Mbit s^-1) = 352.0 km\n (1 Gbit s^-1) = 287.0 km\n\n(b)Max. repeater spacing (50 Mbit s^-1) = 382.0 km\n (1 Gbit s^-1) = 317.0 km\n" } ], "prompt_number": 37 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 13.6, page 888" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nnp=150\nh1=6.626*10**-34 #plancks constant\nc=2.998*10**8 #speed of light\nbf=20*10**12 #optical bandwidth\nh=1.3*10**-6 #wavelength\n\n#Calculation\ntx=(np*h1*c*bf)/h #transmitter power\n\n#Result\nprint'Minimum transmitter power = %.1f mW' %(tx*1000)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Minimum transmitter power = 0.5 mW\n" } ], "prompt_number": 26 } ], "metadata": {} } ] }