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diff --git a/Optical_Communiation_by_Anasuya_Kalavar/chapter4.ipynb b/Optical_Communiation_by_Anasuya_Kalavar/chapter4.ipynb deleted file mode 100755 index 408746a4..00000000 --- a/Optical_Communiation_by_Anasuya_Kalavar/chapter4.ipynb +++ /dev/null @@ -1,413 +0,0 @@ -{ - "metadata": { - "name": "", - "signature": "sha256:c80be9ee73d5adb979ad6bf2343ea3cff1243505e35fc82560bd445f960931b7" - }, - "nbformat": 3, - "nbformat_minor": 0, - "worksheets": [ - { - "cells": [ - { - "cell_type": "heading", - "level": 1, - "metadata": {}, - "source": [ - "Chapter4 - Signal Degradation in fibers" - ] - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.3.1, page 4-4" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "from __future__ import division\n", - "from numpy import sqrt, pi, log10\n", - "L=10 #fiber length in km\n", - "Pin=150*10**-6 #input power\n", - "Pout=5*10**-6 #output power\n", - "ln=20 #length of optical link\n", - "interval=1 #splices after interval of 1 km\n", - "l=1.2 #loss due to 1 splice\n", - "attenuation=10*log10(Pin/Pout) \n", - "alpha=attenuation/L \n", - "attenuation_loss=alpha*20 \n", - "splices_loss=(ln-interval)*l \n", - "total_loss=attenuation_loss+splices_loss \n", - "power_ratio=10**(total_loss/10) \n", - "print \"Signal attenuation is %.2f dBs.\\nSignal attenuation is %.3f dB/Km.\\nTotal loss in 20 Km fiber is %.2f dbs.\\nTotal attenuation is %.2f dBs.\\ninput/output ratio is %0.e.\" %(attenuation,alpha,attenuation_loss,total_loss,power_ratio) \n", - "# Answer wrong for last part." - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "Signal attenuation is 14.77 dBs.\n", - "Signal attenuation is 1.477 dB/Km.\n", - "Total loss in 20 Km fiber is 29.54 dbs.\n", - "Total attenuation is 52.34 dBs.\n", - "input/output ratio is 2e+05.\n" - ] - } - ], - "prompt_number": 32 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.6.1, page 4-12" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "from numpy import exp\n", - "beta_c=8*10**-11 #isothermal compressibility\n", - "n=1.46 #refractive index\n", - "P=0.286 #photoelastic constat\n", - "k=1.38*10**-23 #Boltzmnn constant\n", - "T=1500 #temperature\n", - "L=1000 #length\n", - "lamda=1000*10**-9 #wavelength\n", - "gamma_r = 8*(3.14**3)*(P**2)*(n**8)*beta_c*k*T/(3*(lamda**4)) #computing coefficient\n", - "attenuation=exp(-gamma_r*L) #computing attenuation\n", - "print \"Attenuation due to Rayleigh scattering is %.3f.\" %(attenuation) " - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "Attenuation due to Rayleigh scattering is 0.794.\n" - ] - } - ], - "prompt_number": 10 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.6.2, page 4-12" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "beta_c=7*10**-11 #isothermal compressibility\n", - "n=1.46 #refractive index\n", - "P=0.29 #photoelastic constat\n", - "k=1.38*10**-23 #Boltzmnn constant\n", - "T=1400 #temperature\n", - "L=1000 #length\n", - "lamda=0.7*10**-6 #wavelength\n", - "gamma_r = 8*(3.14**3)*(P**2)*(n**8)*beta_c*k*T/(3*(lamda**4)) #computing coefficient\n", - "attenuation=exp(-gamma_r*L) #computing attenuation\n", - "gamma_r=gamma_r\n", - "print \"Raleigh Scattering corfficient is %.3e per meter\" %(gamma_r) \n", - "#Attenuation is not calcualted in textbook\"\n", - "print \"Attenuation due to Rayleigh scattering is %.3f\" %(attenuation) \n", - "#answer for Raleigh Scattering corfficient in the book is given as 0.804d-3, deviation of 0.003d-3" - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "Raleigh Scattering corfficient is 8.074e-04 per meter\n", - "Attenuation due to Rayleigh scattering is 0.446\n" - ] - } - ], - "prompt_number": 17 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.7.1, page 4-17" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "d=5 #core diameter\n", - "alpha=0.4 #attenuation\n", - "B=0.5 #Bandwidth\n", - "lamda=1.4 #wavelength\n", - "PB=4.4*10**-3*d**2*lamda**2*alpha*B #computing threshold power for SBS\n", - "PR=5.9*10**-2*d**2*lamda*alpha #computing threshold power for SRS\n", - "PB=PB*10**3 \n", - "PR=PR*10**3 \n", - "print \"Threshold power for SBS is %.1f mW.\\nThreshold power for SRS is %.3f mW.\" %(PB,PR) \n", - "#NOTE - Calculation error in the book while calculating threshold for SBS.\n", - "#Also, while calculating SRS, formula is taken incorrectly, \n", - "#Bandwidth is multiplied in second step, which is not in the formula.\") " - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "Threshold power for SBS is 43.1 mW.\n", - "Threshold power for SRS is 826.000 mW.\n" - ] - } - ], - "prompt_number": 19 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.8.1, page 4-18" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "n1=1.5 #refractive index of core\n", - "delta=0.03/100 #relative refractive index\n", - "lamda=0.82*10**-6 #wavelength\n", - "n2=sqrt(n1**2-2*delta*n1**2) #computing cladding refractive index\n", - "Rc=(3*n1**2*lamda)/(4*3.14*(n1**2-n2**2)**1.5) #computing critical radius\n", - "Rc=Rc*10**3 \n", - "print \"Critical radius is %.f micrometer.\" %(Rc) " - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "Critical radius is 9 micrometer.\n" - ] - } - ], - "prompt_number": 22 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.8.2, page 4-20" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "n1=1.45 #refractive index of core\n", - "delta=3.0/100 #relative refractive index\n", - "lamda=1.5*10**-6 #wavelength\n", - "a=5*10**-6 #core radius\n", - "n2=sqrt(n1**2-2*delta*n1**2) #computing cladding refractive index\n", - "Rc=(3*n1**2*lamda)/(4*3.14*(n1**2-n2**2)**0.5) #computing critical radius for single mode\n", - "Rc=Rc*10**6 \n", - "print \"Critical radius is %.2f micrometer\" %(Rc) \n", - "lamda_cut_off= 2*3.14*a*n1*sqrt(2*delta)/2.405 \n", - "RcSM= (20*lamda/(n1-n2)**1.5)*(2.748-0.996*lamda/lamda_cut_off)**-3 #computing critical radius for single mode\n", - "RcSM=RcSM*10**6 \n", - "print \"Critical radius for single mode fiber is %.2f micrometer.\" %(RcSM) \n", - "#Calculation error in the book.(2.748-0.996*lamda/lamda_cut_off)**-3 in this term raised to -3 is not taken in the book." - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "Critical radius is 2.12 micrometer\n", - "Critical radius for single mode fiber is 226.37 micrometer.\n" - ] - } - ], - "prompt_number": 24 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.13.1, page 4-28" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "lamda=1550*10**-9 \n", - "lamda0=1.3*10**-6 \n", - "s0=0.095 \n", - "Dt=lamda*s0/4*(1-(lamda0/lamda)**4) #computing material dispersion\n", - "Dt=Dt*10**9 \n", - "print \"Material dispersion at 1550 nm is %.1f ps/nm/km\" %Dt\n", - "#answer in the book is wrong." - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "Material dispersion at 1550 nm is 18.6 ps/nm/km\n" - ] - } - ], - "prompt_number": 26 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.14.1, page 4-33" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "tau=0.1*10**-6 #pulse broadning\n", - "dist=20*10**3 #distance\n", - "Bopt=1/(2*tau) #computing optical bandwidth\n", - "Bopt=Bopt*10**-6 \n", - "dispertion=tau/dist #computing dispersion\n", - "dispertion=dispertion*10**12 \n", - "BLP=Bopt*dist #computing Bandwidth length product\n", - "BLP=BLP*10**-3 \n", - "print \"optical bandwidth is %d MHz.\\nDispersion per unit length is %d ns/km.\\nBandwidth length product is %d MHz.km.\" %(Bopt,dispertion,BLP) " - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "optical bandwidth is 5 MHz.\n", - "Dispersion per unit length is 5 ns/km.\n", - "Bandwidth length product is 100 MHz.km.\n" - ] - } - ], - "prompt_number": 27 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.15.1, page 4-34" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "RSW=0.0012 #relative spectral width\n", - "lamda=0.90*10**-6 #wavelength\n", - "L=1 #distance in km (assumed)\n", - "P=0.025 #material dispersion parameter\n", - "c=3*10**5 #speed of light in km/s\n", - "M=10**3*P/(c*lamda) #computing material dispersion\n", - "sigma_lamda=RSW*lamda \n", - "sigmaM=sigma_lamda*L*M*10**7 #computing RMS pulse broadning\n", - "sigmaB=25*L*M*10**-3 \n", - "print \"Material dispersion parameter is %.2f ps/nm/km.\\nRMS pulsr broadning when sigma_lamda is 25 is %.1f ns/km.\\nRMS pulse broadning is %.2f ns/km.\" %(M,sigmaB,sigmaM) \n", - "#answer in the book for RMS pulse broadning is wrong." - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "Material dispersion parameter is 92.59 ps/nm/km.\n", - "RMS pulsr broadning when sigma_lamda is 25 is 2.3 ns/km.\n", - "RMS pulse broadning is 1.00 ns/km.\n" - ] - } - ], - "prompt_number": 29 - }, - { - "cell_type": "heading", - "level": 2, - "metadata": {}, - "source": [ - "Example 4.17.1, page 4-37" - ] - }, - { - "cell_type": "code", - "collapsed": false, - "input": [ - "L=10 #length of optical link\n", - "n1=1.49 #refractive index\n", - "c=3*10**8 #speed of light\n", - "delta=1.0/100 #relative refractive index\n", - "delTS=L*n1*delta/c #computing delay difference\n", - "delTS=delTS*10**12 \n", - "sigmaS=L*n1*delta/(2*sqrt(3)*c) #computing rms pulse broadning\n", - "sigmaS=sigmaS*10**12 \n", - "B=1/(2*delTS) #computing maximum bit rate\n", - "B=B*10**3 \n", - "B_acc=0.2/(sigmaS) #computing accurate bit rate\n", - "B_acc=B_acc*10**3 \n", - "BLP=B_acc*L #computing Bandwidth length product\n", - "print \"Delay difference is %d ns.\\nRMS pulse broadning is %.1f ns.\\nBit rate is %.1f Mbit/s.\\nAccurate bit rate is %.3f Mbits/s.\\nBandwidth length product is %.1f MHz.km\" %(delTS,sigmaS,B,B_acc,BLP) \n", - "#answer for maximum bit rate is given as 1.008 Mb/s, deviation of 0.008 Mb/s." - ], - "language": "python", - "metadata": {}, - "outputs": [ - { - "output_type": "stream", - "stream": "stdout", - "text": [ - "Delay difference is 496 ns.\n", - "RMS pulse broadning is 143.4 ns.\n", - "Bit rate is 1.0 Mbit/s.\n", - "Accurate bit rate is 1.395 Mbits/s.\n", - "Bandwidth length product is 13.9 MHz.km\n" - ] - } - ], - "prompt_number": 31 - } - ], - "metadata": {} - } - ] -}
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