{ "metadata": { "name": "", "signature": "sha256:d6b4557b658267af4573aff55394c33f7ae58a19c1bc5291838cb933f306de2e" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "5: Polarization" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.1, Page number 113" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#importing modules\n", "from __future__ import division\n", "import math\n", "\n", "#Variable declaration\n", "mew_g = 1.72; #Refractive index of glass\n", "mew_w = 4/3; #Refractive index of water\n", "\n", "#Calculation\n", "#For polarization to occur on flint glass, tan(i) = mew_g/mew_w\n", "#Solving for i\n", "i_g = math.atan(mew_g/mew_w); #angle of incidence for complete polarization for flint glass(rad)\n", "a = 180/math.pi; #conversion factor from radians to degrees\n", "i_g = i_g*a; #angle of incidence(degrees)\n", "i_g = math.ceil(i_g*10**2)/10**2; #rounding off the value of i_g to 2 decimals\n", "#For polarization to occur on water, tan(i) = mew_w/mew_g\n", "#Solving for i\n", "i_w = math.atan(mew_w/mew_g); #angle of incidence for complete polarization for water(rad)\n", "i_w = i_w*a; #angle of incidence(degrees)\n", "i_w = math.ceil(i_w*10**3)/10**3; #rounding off the value of i_w to 3 decimals\n", "\n", "#Result\n", "print \"The angle of incidence for complete polarization to occur on flint glass is\",i_g, \"degrees\"\n", "print \"The angle of incidence for complete polarization to occur on water is\",i_w, \"degrees\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The angle of incidence for complete polarization to occur on flint glass is 52.22 degrees\n", "The angle of incidence for complete polarization to occur on water is 37.783 degrees\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.2, Page number 113" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#importing modules\n", "from __future__ import division\n", "import math\n", "\n", "#Variable declaration\n", "I0 = 1; #For simplicity, we assume the intensity of light falling on the second Nicol prism to be unity(W/m**2)\n", "theta = 30; #Angle through which the crossed Nicol is rotated(degrees)\n", "\n", "#Calculation\n", "theeta = 90-theta; #angle between the planes of transmission after rotating through 30 degrees\n", "a = math.pi/180; #conversion factor from degrees to radians\n", "theeta = theeta*a; ##angle between the planes of transmission(rad)\n", "I = I0*math.cos(theeta)**2; #Intensity of the emerging light from second Nicol(W/m**2)\n", "T = (I/(2*I0))*100; #Percentage transmission of incident light\n", "T = math.ceil(T*100)/100; #rounding off the value of T to 2 decimals\n", "\n", "#Result\n", "print \"The percentage transmission of incident light after emerging through the Nicol prism is\",T, \"%\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The percentage transmission of incident light after emerging through the Nicol prism is 12.51 %\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.3, Page number 113" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#importing modules\n", "from __future__ import division\n", "import math\n", "\n", "#Variable declaration\n", "lamda = 6000; #Wavelength of incident light(A)\n", "mew_e = 1.55; #Refractive index of extraordinary ray\n", "mew_o = 1.54; #Refractive index of ordinary ray\n", "\n", "#Calculation\n", "lamda = lamda*10**-8; #Wavelength of incident light(cm)\n", "t = lamda/(4*(mew_e-mew_o)); #Thickness of Quarter Wave plate of positive crystal(cm)\n", "\n", "#Result\n", "print \"The thickness of Quarter Wave plate is\",t, \"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The thickness of Quarter Wave plate is 0.0015 cm\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.4, Page number 114" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#Calculation\n", "#the thickness of a half wave plate of calcite for wavelength lamda is\n", "#t = lamda/(2*(mew_e - mew_o)) = (2*lamda)/(4*(mew_e - mew_o))\n", "\n", "#Result\n", "print \"The half wave plate for lamda will behave as a quarter wave plate for 2*lamda for negligible variation of refractive index with wavelength\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The half wave plate for lamda will behave as a quarter wave plate for 2*lamda for negligible variation of refractive index with wavelength\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.5, Page number 114" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#importing modules\n", "from __future__ import division\n", "import math\n", "\n", "#Variable declaration\n", "lamda = 500; #Wavelength of incident light(nm)\n", "mew_e = 1.5508; #Refractive index of extraordinary ray\n", "mew_o = 1.5418; #Refractive index of ordinary ray\n", "t = 0.032; #Thickness of quartz plate(mm)\n", "\n", "#Calculation\n", "lamda = lamda*10**-9; #Wavelength of incident light(m)\n", "t = t*10**-3; #Thickness of quartz plate(m)\n", "dx = (mew_e - mew_o)*t; #Path difference between E-ray and O-ray(m)\n", "dphi = (2*math.pi)/lamda*dx; #Phase retardation for quartz for given wavelength(rad)\n", "dphi = dphi/math.pi;\n", "\n", "#Result\n", "print \"The phase retardation for quartz for given wavelength is\",dphi, \"pi rad\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The phase retardation for quartz for given wavelength is 1.152 pi rad\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example number 5.6, Page number 114" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#importing modules\n", "import math\n", "\n", "#Variable declaration\n", "C = 52; #Critical angle for total internal reflection(degrees)\n", "\n", "#Calculation\n", "a = math.pi/180; #conversion factor from degrees to radians\n", "C = C*a; #Critical angle for total internal reflection(rad)\n", "#From Brewster's law, math.tan(i_B) = 1_mew_2\n", "#Also math.sin(C) = 1_mew_2, so that math.tan(i_B) = math.sin(C), solving for i_B\n", "i_B = math.atan(math.sin(C)); #Brewster angle at the boundary(rad)\n", "b = 180/math.pi; #conversion factor from radians to degrees\n", "i_B = i_B*b; #Brewster angle at the boundary(degrees)\n", "\n", "#Result\n", "print \"The Brewster angle at the boundary between two materials is\",int(i_B), \"degrees\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Brewster angle at the boundary between two materials is 38 degrees\n" ] } ], "prompt_number": 13 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [], "prompt_number": 10 } ], "metadata": {} } ] }