{ "metadata": { "name": "", "signature": "sha256:0c5a5b237d1d9ee2de03397e0c595a70fe68a27ab5ea34fc9d5e4643a075bb47" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Ch-26, Optical properties of materials and materials for opto electronic devices" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "example-26.1 page no-769" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "#given\n", "#wavelength of light\n", "lamda=5.893*10**-7 #m\n", "#plank's constant\n", "h=6.626*10**-34 #J s\n", "#velocity of light \n", "c=3*10**8 #m/s\n", "#energy of photon\n", "Ephoton=h*c/lamda #J\n", "#we know that 1eV=1.6*10**-19 J\n", "#so\n", "EPhoton=Ephoton/(1.6*10**-19) #eV\n", "print \" the energy of photon is %.23f J or %f eV\"%(Ephoton,EPhoton)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " the energy of photon is 0.00000000000000000033732 J or 2.108222 eV\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "example-26.2 page no-769" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import exp\n", "#given\n", "##thickness of sample\n", "t=0.45*10**-4 #cm\n", "#energy of light\n", "E1=3 #eV\n", "#absorption coefficient\n", "alpha=50000 #per cm\n", "#incident power on the sample\n", "I0=15*10**-3 #W\n", "#we know that\n", "#intensity of transmitted light is given by\n", "It=I0*exp(-alpha*t) #W or J/s\n", "#thus total energy absorbed is \n", "Iabsorbed=I0-It #W or J/s\n", "print \" total energy absorbed is %0.3e J/s\"%(Iabsorbed)\n", "#plank's constant\n", "h=6.626*10**-34 #J s\n", "#energy of outgoing radiation\n", "E2=2.35 #eV\n", "#fraction of each photon energy unit which is converted ton heat\n", "E=(E1-E2)/E1 \n", "#therefore total amount of energy converted to heat per second is\n", "EC=E*Iabsorbed #J/s\n", "print \" total amount of energy coverted to heat is %0.3e J/s\"%(EC)\n", "#charge on an electron\n", "e=1.6*10**-19 #C\n", "#no of photons = nphoton \n", "nphoton=Iabsorbed/(e*E1) #photons/sec (calculation mistake is there in book)\n", "print \" the no of photon given off from recombination is %0.3e photons/sec\"%(nphoton)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " total energy absorbed is 1.342e-02 J/s\n", " total amount of energy coverted to heat is 2.907e-03 J/s\n", " the no of photon given off from recombination is 2.796e+16 photons/sec\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "example-26.3 page no-783" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "#energy of photon\n", "E=1.5*10**-19 #J\n", "#quantum eficiency\n", "muquantam=0.6\n", "#photon current\n", "Iopc=3*10**-6 #A\n", "#speed of light\n", "c=3*10**8 #m/s\n", "#plank's constant\n", "h=6.626*10**-34 #J s\n", "#wavelength at which the photodiode is operatng\n", "lamda=h*c/E*10**6 #micro m\n", "#responsivity of diode\n", "R=0.64\n", "#incident optical power is given by\n", "Piop=Iopc/R*10**6 #micro W\n", "print \"wavelength at which photodiode is operating is %0.3f micro m \\n and incident optical power is %0.3f micro W\"%(lamda,Piop)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "wavelength at which photodiode is operating is 1.325 micro m \n", " and incident optical power is 4.688 micro W\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "example-26.4 page no-784" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import asin, pi\n", "#given\n", "#refractive index of core and cladding\n", "mucladding=1.47\n", "mucore=1.50\n", "#critocal angle at the core cladding interface\n", "thetac=asin(mucladding/mucore) *180/(pi) #degrees\n", "print \"the critical angle at core cladding interface is %0.3f degrees\"%(thetac)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the critical angle at core cladding interface is 78.522 degrees\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "example-26.5 page no-784" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "#energy band gap\n", "Eg=0.75*1.6*10**-19 #J\n", "#plank's constant\n", "h=6.626*10**-34 #Js\n", "#speed of light\n", "c=3*10**8 #m/s\n", "#wavelength of light\n", "lamda=h*c/Eg*10**10 #A\n", "print \" wavelength of light is %.f A\"%(lamda)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " wavelength of light is 16565 A\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "example-26.7 page no-784" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "#frequency of light\n", "f=1.5*10**9*10**6 #Hz\n", "#pank's constant\n", "h=6.626*10**-34 #J s\n", "#threshold frequency is\n", "f0=1.2*10**9*10**6 #Hz\n", "#maximum energy of emitted photoelectron is\n", "Emax=h*(f-f0)/(1.6*10**-19) #eV\n", "print \"The maximum enery of the emitted photoe lectron is %0.3f eV\"%(Emax)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The maximum enery of the emitted photoe lectron is 1.242 eV\n" ] } ], "prompt_number": 8 } ], "metadata": {} } ] }