diff options
Diffstat (limited to 'Optical_Communication/Chapter_2.ipynb')
| -rwxr-xr-x | Optical_Communication/Chapter_2.ipynb | 1146 |
1 files changed, 1146 insertions, 0 deletions
diff --git a/Optical_Communication/Chapter_2.ipynb b/Optical_Communication/Chapter_2.ipynb new file mode 100755 index 00000000..ddfaa1d5 --- /dev/null +++ b/Optical_Communication/Chapter_2.ipynb @@ -0,0 +1,1146 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:afd6588cf456d4d425f74443bb32014c9097e23d883f51c38473cadd2c6f5ba9" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 2: Optical Fibers" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.1, Page number 49" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine maximum thickness of film'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 3.5 #core refractive index\n", + "n2 = 3.0 #cladding refractive index\n", + "v = 6 #no. of modes\n", + "lamda = 1.5 #propagating wavelength(um)\n", + "\n", + "#Calculations\n", + "theta_c = math.degrees(math.asin(n2/n1))\n", + "h = (2*math.pi*v*lamda)/(2*math.pi*n1*math.cos(math.radians(theta_c)))\n", + "\n", + "#Result\n", + "print \"The thickness of the film should be less than\",round(h),\"um\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The thickness of the film should be less than 5.0 um\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.2, Page number 50" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''find the angle of acceptance and crtitical angle'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.53 #core refractive index\n", + "n2 = 1.48 #cladding refractive index\n", + "n0 = 1 #refractive index for air\n", + "\n", + "#calculations\n", + "theta_a = math.degrees(math.asin(((n1**2-n2**2)**0.5)/n0)) \n", + "\n", + "theta_c = math.degrees(math.asin(n2/n1))\n", + "\n", + "#Result\n", + "print \"Angle of acceptance =\",round(theta_a,2),\"degrees\"\n", + "print \"Critical angle =\",round(theta_c,2),\"degrees\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Angle of acceptance = 22.83 degrees\n", + "Critical angle = 75.31 degrees\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.3, Page number 50" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine the numerical aperture'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "v = 26.6 #frequency(Hz)\n", + "lamda = 1.3 #propagating wavelength(um)\n", + "a = 25 #core radius(um)\n", + "\n", + "#Calculation\n", + "NA = (v*lamda)/(2*math.pi*a)\n", + "\n", + "#Result\n", + "print \"Numerical aperture =\",round(NA,2)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Numerical aperture = 0.22\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.4, Page number 51" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine the numerical aperture'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.4675 #core refractive index\n", + "n2 = 1.4622 #cladding refractive index\n", + "\n", + "#Calculation\n", + "NA = math.sqrt(n1**2-n2**2)\n", + "\n", + "#Result\n", + "print \"Numerical aperture =\",round(NA,3)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Numerical aperture = 0.125\n" + ] + } + ], + "prompt_number": 5 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.5, Page number 51" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine cut-off wavelength for step index fiber'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.5 #core refractive index\n", + "n2 = 1.47 #cladding refractive index\n", + "a = 4 #core radius(um)\n", + "\n", + "#Calculation\n", + "lamda_c = (2*math.pi*a*((n1**2-n2**2)**0.5))/2.405\n", + "\n", + "#Result\n", + "print \"The cut-off wavelength is\",round(lamda_c,2),\"um\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The cut-off wavelength is 3.12 um\n" + ] + } + ], + "prompt_number": 7 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.6, Page number 51" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine maximum diameter of the core for single mode fiber'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.55 #core refractive index\n", + "n2 = 1.48 #cladding refractive index\n", + "lamda = 1.55 #wavelength(um)\n", + "\n", + "#Calculations\n", + "a = (2.405*lamda)/(2*math.pi*(n1**2-n2**2)**0.5)\n", + "d = 2*a #diameter\n", + "\n", + "#Result\n", + "print \"Maximum diameter of the core is\",round(d,2),\"um\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Maximum diameter of the core is 2.58 um\n" + ] + } + ], + "prompt_number": 10 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.7, Page number 52" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine the number of modes propagating'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.48 #core refractive index\n", + "n2 = 0.01 #cladding refractive index\n", + "a = 25 #core radius(um)\n", + "lamda = 0.84 #Wavelength(um)\n", + "\n", + "#Calculation\n", + "m = 2*(2*math.pi/lamda)**2*(a**2/2)*(n1**2-n2**2)\n", + "v = math.sqrt(2*m)\n", + "\n", + "#Result\n", + "print \"Number of modes =\",v, \"(Calculation mistake in textbook while calculating 'm'. Hence, the answer differs)\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Number of modes = 391.074660134 (Calculation mistake in textbook while calculating 'm'. Hence, the answer differs)\n" + ] + } + ], + "prompt_number": 14 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.8, Page number 52" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine the number of modes for multimode fiber and calculate the same when lamda is changed to 1.3um'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.475 #core refractive index\n", + "n2 = 1.472 #cladding refractive index\n", + "a = 20 #core radius(um)\n", + "lamda = 0.85 #Wavelength(um)\n", + "\n", + "#Calculation\n", + "v = (2*math.pi*a*math.sqrt((n1**2-n2**2)))/lamda\n", + "M1 = v**2/2\n", + "\n", + "lamda2 = 1.3 #um\n", + "v2 = (2*math.pi*a*math.sqrt((n1**2-n2**2)))/lamda2\n", + "M2 = v2**2/2\n", + "\n", + "#Results\n", + "print \"Number of modes when lamda is changed =\",round(M1) #v is calculated wrongly in the book and answer for case a M not given\n", + "print \"Number of modes when lamda is changed =\",round(M2)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Number of modes when lamda is changed = 97.0\n", + "Number of modes when lamda is changed = 41.0\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.9, Page number 53" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine the numerical aperture'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.5 #core refractive index\n", + "n2 = 1.48 #cladding refractive index\n", + "\n", + "#Calculation\n", + "NA = math.sqrt(n1**2-n2**2)\n", + "\n", + "#Result\n", + "print \"Numerical aperture =\",round(NA,5)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Numerical aperture = 0.24413\n" + ] + } + ], + "prompt_number": 21 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.10, Page number 53" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine core radius, NA and maximum acceptance angle'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.450 #core refractive index\n", + "n2 = 1.447 #cladding refractive index\n", + "lamda = 1.3 #Wavelength(um)\n", + "\n", + "#Calculation\n", + "v = 2.405\n", + "a = (v*lamda)/(2*math.pi*math.sqrt((n1**2-n2**2)))\n", + "\n", + "NA = math.sqrt(n1**2-n2**2)\n", + "\n", + "theta_max = math.degrees(math.asin(NA))\n", + "\n", + "#Results\n", + "print \"Core radius =\",round(a,3),\"um\"\n", + "print \"Numerical aperture =\",round(NA,4)\n", + "print \"Maximum acceptance angle =\",round(theta_max,3),\"degrees\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Core radius = 5.338 um\n", + "Numerical aperture = 0.0932\n", + "Maximum acceptance angle = 5.349 degrees\n" + ] + } + ], + "prompt_number": 37 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.11, Page number 53" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine critical angle at core cladding interface, NA and acceptance angle'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.50 #core refractive index\n", + "n2 = 1.47 #cladding refractive index\n", + "\n", + "#calculations\n", + "theta_c = math.degrees(math.asin(n2/n1))\n", + "\n", + "NA = math.sqrt(n1**2-n2**2)\n", + "\n", + "theta_a = math.degrees(math.asin(NA))\n", + "\n", + "#Result\n", + "print \"Critical angle at core cladding interface =\",round(theta_c,1),\"degrees\"\n", + "print \"Numerical aperture =\",round(NA,2)\n", + "print \"Maximum acceptance angle =\",round(theta_a,1),\"degrees\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Critical angle at core cladding interface = 78.5 degrees\n", + "Numerical aperture = 0.3\n", + "Maximum acceptance angle = 17.4 degrees\n" + ] + } + ], + "prompt_number": 38 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.12, Page number 55" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine the acceptance angle for skew rays'''\n", + "\n", + "#Variable declaration\n", + "NA = 0.4 #numerical aperture\n", + "#Since skew rays change direction by 100 degrees at each reflection,\n", + "r = 50 #degrees\n", + "\n", + "#Calculations\n", + "theta_as = math.degrees(math.asin(NA/math.cos(math.radians(r))))\n", + "\n", + "#print\n", + "print \"Acceptance angle =\",round(theta_as,1),\"degrees\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Acceptance angle = 38.5 degrees\n" + ] + } + ], + "prompt_number": 39 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.13, Page number 55" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine normalized frequency and number of guided modes'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.48 #core refractive index\n", + "lamda = 0.85 #wavelength(um)\n", + "a = 80/2 #core radius(um)\n", + "delta = 1.5/100 #relative index difference\n", + "\n", + "#Calculations\n", + "v = (2*math.pi*a*n1*(2*delta)**0.5)/lamda\n", + "\n", + "M = v**2/2\n", + "\n", + "#Results\n", + "print \"Normalized frequency =\",round(v,1),\"Hz\"\n", + "print \"Number of guided modes =\",round(M)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Normalized frequency = 75.8 Hz\n", + "Number of guided modes = 2872.0\n" + ] + } + ], + "prompt_number": 40 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.14, Page number 56" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine cut off value for normalized frequency and maximum core radius'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.5 #core refractive index\n", + "lamda = 1.3 #wavelength(um)\n", + "delta = 1./100. #relative index difference\n", + "alpha = 2\n", + "\n", + "#Calculations\n", + "v = 2.4*(1+2/alpha)**0.5\n", + "\n", + "a = (v*lamda)/(2*math.pi*n1*(2*delta)**0.5)\n", + "\n", + "#Results\n", + "print \"Cut off value for normalized frequency =\",round(v,2)\n", + "print \"Maximum core radius =\",round(a,2),\"um\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Cut off value for normalized frequency = 3.39\n", + "Maximum core radius = 3.31 um\n" + ] + } + ], + "prompt_number": 42 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.15, Page number 56" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine cut-off wavelength for step index fiber'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.46 #core refractive index\n", + "a = 4.5 #core radius(um)\n", + "delta = 0.25/100\n", + "\n", + "#Calculation\n", + "lamda_c = (2*math.pi*a*n1*(2*delta)**0.5)/2.405\n", + "\n", + "#Result\n", + "print \"The cut-off wavelength is\",round(lamda_c,3),\"um\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The cut-off wavelength is 1.214 um\n" + ] + } + ], + "prompt_number": 43 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.16, Page number 57" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine the numerical aperture and acceptance angle'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.45 #core refractive index\n", + "n2 = 1.4 #cladding refractive index\n", + "\n", + "#Calculation\n", + "NA = math.sqrt(n1**2-n2**2)\n", + "\n", + "theta_m = math.degrees(math.asin(NA))\n", + "\n", + "#Result\n", + "print \"Numerical aperture =\",round(NA,4)\n", + "print \"Acceptance angle =\",round(theta_m,2),\"degrees\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Numerical aperture = 0.3775\n", + "Acceptance angle = 22.18 degrees\n" + ] + } + ], + "prompt_number": 44 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.17, Page number 57" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Calculate cladding index, crtical internal reflection angle, external critical acceptance angle and numerical aperture'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.5 #core refractive index\n", + "delta = 0.0005\n", + "\n", + "#Calculations\n", + "n2 = n1*(1-delta)\n", + "\n", + "theta_c = math.degrees(math.asin(n2/n1))\n", + "\n", + "n0 = 1 #refractive index for air\n", + "theta_m = math.degrees(math.asin(((n1**2-n2**2)**0.5)/n0))\n", + "\n", + "NA = n1*math.sqrt(2*delta)\n", + "\n", + "#Results\n", + "print \"Cladding index =\",round(n2,5)\n", + "print \"Crtical internal reflection angle =\",round(theta_c,1),\"degrees\"\n", + "print \"External critical acceptance angle =\",round(theta_m,2),\"Degrees\"\n", + "print \"Numerical aperture =\",round(NA,4)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Cladding index = 1.49925\n", + "Crtical internal reflection angle = 88.2 degrees\n", + "External critical acceptance angle = 2.72 Degrees\n", + "Numerical aperture = 0.0474\n" + ] + } + ], + "prompt_number": 46 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.18, Page number 58" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine acceptance angle for fiber in water'''\n", + "\n", + "#Variable declaration\n", + "NA = 0.20 #numerical aperture\n", + "n2 = 1.59 #cladding refractive index\n", + "n0 = 1.33 #refractive index for water \n", + "\n", + "#Calculations\n", + "n1 = math.sqrt(NA**2+n2**2)\n", + "NA = math.sqrt(n1**2-n2**2)/n0\n", + "theta_m = math.degrees(math.asin(NA))\n", + "\n", + "#Result\n", + "print \"Acceptance angle for fiber in water =\",round(theta_m,1),\"degrees\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Acceptance angle for fiber in water = 8.6 degrees\n" + ] + } + ], + "prompt_number": 47 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.19, Page number 58" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine the numerical aperture and acceptance angle'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.55 #core refractive index\n", + "n2 = 1.51 #cladding refractive index\n", + "\n", + "#Calculation\n", + "delta = (n1-n2)/n1\n", + "NA = 2*math.sqrt(delta)\n", + "\n", + "theta_m = math.degrees(math.asin(NA))\n", + "\n", + "#Result\n", + "print \"Numerical aperture =\",round(NA,4)\n", + "print \"Acceptance angle =\",round(theta_m,2),\"degrees\"\n", + "print \"\\nCalculation mistakes in textbook. Hence, the answers differ.\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Numerical aperture = 0.3213\n", + "Acceptance angle = 18.74 degrees\n", + "\n", + "Calculation mistakes in textbook. Hence, the answers differ.\n" + ] + } + ], + "prompt_number": 49 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.20, Page number 59" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine normalized frequency'''\n", + "\n", + "#Variable declaration\n", + "n = 1.45 #core refractive index\n", + "lamda = 0.1 #wavelength(um)\n", + "a = 60/2 #core radius(um)\n", + "NA = 0.16 #numerical aperture\n", + "\n", + "#Calculations\n", + "v = (2*math.pi*a*NA)/lamda\n", + "\n", + "#Results\n", + "print \"Normalized frequency =\",round(v,1),\"(Calculation mistake in textbook)\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Normalized frequency = 301.6 (Calculation mistake in textbook)\n" + ] + } + ], + "prompt_number": 50 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.21, Page number 59" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Calculate NA and multi path dospersion per unit length'''\n", + "\n", + "#Variable declaration\n", + "c = 3.*10**8 #speed of light in vacuum(m/s)\n", + "v = 2.*10**8 #speed of light in core(m/s)\n", + "theta_c = 75 #cricial angle(degrees)\n", + "\n", + "#Calculations\n", + "n1 = c/v\n", + "n2 = n1*math.sin(math.radians(theta_c))\n", + "NA = math.sqrt(n1**2-n2**2)\n", + "\n", + "delta_n = n1-n2\n", + "md = (n1/n2)*(delta_n/c) #multipath dispersion\n", + "\n", + "#Results\n", + "print \"Numerical aperture =\",round(NA,2)\n", + "print \"Multi path dospersion per unit length =\",round((md/1E-9),3),\"*10^-9 s/m\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Numerical aperture = 0.39\n", + "Multi path dospersion per unit length = 0.176 *10^-9 s/m\n" + ] + } + ], + "prompt_number": 51 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.22, Page number 60" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine maximum thickness of guide slab'''\n", + "\n", + "#Variable declaration\n", + "n1 = 3.6 #core refractive index\n", + "n2 = 3.56 #cladding refractive index\n", + "lamda = 0.85 #wavelength(um)\n", + "#For TE10 mode,\n", + "m = 1\n", + "n = 0\n", + "vc = 2.405 #for planar guide\n", + "\n", + "#Calculation\n", + "a = (vc*lamda)/(2*math.pi*math.sqrt(n1**2-n2**2))\n", + "\n", + "#Result\n", + "print \"Maximum thickness of guide slab =\",round(a,3),\"um\"\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Maximum thickness of guide slab = 0.608 um\n" + ] + } + ], + "prompt_number": 52 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.23, Page number 61" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Calculate diameter of core'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.5 #core refractive index\n", + "lamda = 1.3*10**-6 #wavelength(um)\n", + "delta = 1./100. #relative index difference\n", + "M = 1100\n", + "\n", + "#Calculations\n", + "V = math.sqrt(2*M)\n", + "\n", + "a = (V*lamda)/(2*math.pi*n1*(2*delta)**0.5)\n", + "\n", + "d = 2*a\n", + "\n", + "#Result\n", + "print \"Diameter =\",round(d/1E-5,2),\"um(Calculation mistake in textbook)\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Diameter = 9.15 um(Calculation mistake in textbook)\n" + ] + } + ], + "prompt_number": 6 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.24, Page number 62" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine critical angle and numerical aperture'''\n", + "\n", + "\n", + "#Variable declaration\n", + "n1 = 1.50 #core refractive index\n", + "n2 = 1.46 #cladding refractive index\n", + "\n", + "#Calculation\n", + "theta_c = math.degrees(math.asin(n2/n1))\n", + "\n", + "NA = math.sqrt(n1**2-n2**2)\n", + "\n", + "#Result\n", + "print \"Critical angle =\",round(theta_c,2),\"degrees\"\n", + "print \"Numerical aperture =\",round(NA,2)" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Critical angle = 76.74 degrees\n", + "Numerical aperture = 0.34\n" + ] + } + ], + "prompt_number": 59 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.25, Page number 62" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Determine the acceptance angle for skew rays'''\n", + "\n", + "#Variable declaration\n", + "NA = 0.344 #numerical aperture\n", + "#Since skew rays change direction by 100 degrees at each reflection,\n", + "gamma = 100/2 #degrees\n", + "\n", + "#Calculations\n", + "#For meridional rays\n", + "theta_a = math.degrees(math.asin(NA))\n", + "#For speed rays\n", + "theta_as = math.degrees(math.asin(NA/math.cos(math.radians(gamma))))\n", + "\n", + "#print\n", + "print \"Acceptance angle for meridional rays =\",round(theta_a,2),\"degrees\"\n", + "print \"Acceptance angle for speed rays =\",round(theta_as,2),\"degrees\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Acceptance angle for meridional rays = 20.12 degrees\n", + "Acceptance angle for speed rays = 32.36 degrees\n" + ] + } + ], + "prompt_number": 84 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 2.26, Page number 62" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "'''Calculate the no. of guided modes and cut-off value of normalized frequency'''\n", + "\n", + "import math\n", + "\n", + "#Variable declaration\n", + "n1 = 1.5 #core refractive index\n", + "lamda = 1.55 #wavelength(um)\n", + "delta = 1.3/100. #relative index difference\n", + "alpha = 1.90 #index profile\n", + "a = 40/2 #core radius(um)\n", + "\n", + "#Calculations\n", + "Mg = (alpha/(alpha+2))*((n1*2*math.pi*a)/lamda)**2*delta\n", + "\n", + "Vc = 2.405*math.sqrt(1+2/alpha)\n", + "\n", + "#Results\n", + "print \"Number of guided modes =\",round(Mg)\n", + "print \"Cut-off value of normalized frequency =\",round(Vc,2)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Number of guided modes = 94.0\n", + "Cut-off value of normalized frequency = 3.45\n" + ] + } + ], + "prompt_number": 61 + } + ], + "metadata": {} + } + ] +}
\ No newline at end of file |