{ "metadata": { "name": "Chapter_10" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": "Chapter 10 : Optical amplification, wavelength conversion and regeneration\n" }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 10.1, page 555" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nh=1.5*10**-6 #peak gain wavelength\ndelt=10**-9 #mode spacing\nl=300*10**-6 #length\nc=2.998*10**8 #speed of light\nr=0.09 #facet reflectivities\ngs=3.020\n\n#Calculation\nn=(h**2)/(2*delt*l) #refractive index\na=c/(math.pi*n*l)\nd=1-(math.sqrt(r)*gs)\nf=2*math.sqrt(math.sqrt(r)*gs)\nB=a*math.asin(d/f) #spectral bandwidth\n#Result\nprint'Refractive index of a medium = %.2f'%n\nprint'3dB spectral bandwidth = %.1f GHz'%(B*10**-9)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "Refractive index of a medium = 3.75\n3dB spectral bandwidth = 4.2 GHz\n" } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 10.3, page 562" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\ngs=30 #gain in dB\ng=200 #net gain\nloge=0.434 #log(e)\ngs1=1000\nm=2.2 #mode no\nnsp=4 #spontaneous emission factor\nh1=6.626*10**-34 #plancks constant\nf=1.94*10**14\nB=1.0*10**12 #bandwidth\n\n#Calculation\nL=gs/(10*g*loge) #length of the device\nP=m*nsp*(gs1-1)*h1*f*B #noise power spectral density\n\n#Result\nprint'(a) Length of the device = %.2f mm'%(L*10**3)\nprint'(b) Noise power spectral density = %.2f mW'%(P*10**3)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "(a) Length of the device = 34.56 mm\n(b) Noise power spectral density = 1.13 mW\n" } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 10.4, page 580" }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\nGp=62.2 #parametric peak gain in dB\nlog=10*math.log10(0.25)\nPp=1.4 #signal power in watt\nL=500 #length in meter\nlog2=20*math.log10(2.7182818284)\n\n\n#Calculation\ny=(Gp-log)/(Pp*L*log2) #fiber nonlinear coefficient\nGp2=10*math.log10((y*Pp*L)**2) #parametric gain\n \n#Result\nprint'(a) Fiber nonlinear coefficient = %.2f x 10^-3 W^-1 km^-1'%(y*1000)\nprint'(b) Quadratic gain, Gp = %.2f dB'%(Gp2)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "(a) Fiber nonlinear coefficient = 11.22 x 10^-3 W^-1 km^-1\n(b) Quadratic gain, Gp = 17.90 dB\n" } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": "Example 10.5, page 589 " }, { "cell_type": "code", "collapsed": false, "input": "import math\n\n#Variable declaration\npt=0.5*10**-3 #input signal power\ndpt=0.01*10**-6 #input signal power variation\nh=1.55*10**-6 #signal wavelength\na=-1 #linewidth enhancement factor\ndn=-1.2*10**-26 #differential refractive index\n\n#Calculation\ndelt=(-a*dpt)/(4*math.pi*pt) #frequency chirp\ndg=(4*math.pi*dn)/(h*a) #differential gain\n \n#Result\nprint'(a) Frequency chirp variation = %.2f MHz'%(delt*10**6)\nprint'(b) Differential gain = %.2f x10^-20 m^2'%(dg*10**20)", "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": "(a) Frequency chirp variation = 1.59 MHz\n(b) Differential gain = 9.73 x10^-20 m^2\n" } ], "prompt_number": 4 } ], "metadata": {} } ] }