{
"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": {}
}
]
}