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{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 6: Lasers"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.1, Page 170"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable Declaration\n",
"D=4*1e8;#distance between earth and moon in m\n",
"lamda=16000.*1e-10;#wavelength in meters\n",
"d=1e-3;#aperture in meter\n",
"\n",
"#Calculations & Result\n",
"th=lamda/d;#angular speed\n",
"print 'angular speed is=',th,'rad'\n",
"aos=(D*th)**2;#area of spread \n",
"print 'area of spread is=',aos,'m^2'\n",
"#Incorrect answer in the textbook\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"angular speed is= 0.0016 rad\n",
"area of spread is= 4.096e+11 m^2\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.2, Page 170"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable Declaration\n",
"a1=2*1e-3;#distance from the laser\n",
"a2=3*1e-3;#distance from the laser\n",
"d1=2;#output beam spot diameter\n",
"d2=4;#output beam spot diameter\n",
"\n",
"#Calculation\n",
"th=(a2-a1)/(2*(d2-d1));#angle of divergence\n",
"\n",
"#Result\n",
"print 'angle of divergence',th/1e-3,'*10^-3 rad'\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"angle of divergence 0.25 *10^-3 rad\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 6.3, Page 171"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable Declaration\n",
"D=0.1;#focal length of lens\n",
"lamda=14400*1e-10;#wavelength in meters\n",
"p=100*1e-3;#power of laser beam\n",
"d=10*1e-3;#aperture in meter\n",
"\n",
"#Calculations & Results\n",
"th=lamda/d;#angular speed\n",
"print 'angular speed is=',th/1e-4,'*10^-4 rad'\n",
"aos=(D*th)**2;#area of spread \n",
"print 'area of spread is=',aos/1e-10,'*10^-10 m^2'\n",
"I=p/aos;#'intensity\n",
"print 'intensity is=',round(I/1e7,1),'*10^7 W*m^-2'\n",
"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"angular speed is= 1.44 *10^-4 rad\n",
"area of spread is= 2.0736 *10^-10 m^2\n",
"intensity is= 48.2 *10^7 W*m^-2\n"
]
}
],
"prompt_number": 3
}
],
"metadata": {}
}
]
}
|
