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{
"metadata": {
"name": "Chapter12"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": "12: Holography and Fibre Optics"
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example number 12.1, Page number 271"
},
{
"cell_type": "code",
"collapsed": false,
"input": "#To calculate the critical angle, critical propagation angle and numerical aperture \n\n#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nn1 = 1.43; #Refractive index of fibre core\nn2 = 1.4; #Refractive index of fibre cladding\n\n#Calculation\n#As sin (alpha_c) = n2/n1, solving for alpha_c\nalpha_c = math.asin(n2/n1); #Critical angle for optical fibre(rad)\nalpha_c = alpha_c*57.2957795; #Critical angle for optical fibre(degrees)\nalpha_c = math.ceil(alpha_c*10**3)/10**3; #rounding off the value of alpha_c to 3 decimals\n#AS cos(theta_c) = n2/n1, solving for theta_c\ntheta_c = math.acos(n2/n1); #Critical propagation angle for optical fibre(rad)\ntheta_c = theta_c*57.2957795; #Critical propagation angle for optical fibre(degrees)\ntheta_c = math.ceil(theta_c*10**2)/10**2; #rounding off the value of theta_c to 2 decimals\nNA = math.sqrt(n1**2 - n2**2); #Numerical aperture for optical fibre\nNA = math.ceil(NA*10**3)/10**3; #rounding off the value of NA to 3 decimals\n\n#Result\nprint \"The critical angle for optical fibre is\",alpha_c, \"degrees\"\nprint \"The critical propagation angle for optical fibre is\",theta_c, \"degrees\"\nprint \"Numerical aperture for optical fibre is\",NA\n",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "The critical angle for optical fibre is 78.244 degrees\nThe critical propagation angle for optical fibre is 11.76 degrees\nNumerical aperture for optical fibre is 0.292\n"
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example number 12.2, Page number 271"
},
{
"cell_type": "code",
"collapsed": false,
"input": "#To calculate the numerical aperture, acceptance angle and relative refractive index difference\n\n#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nn1 = 1.45; #Refractive index of fibre core\nn2 = 1.4; #Refractive index of fibre cladding\n\n#Calculation\nNA = math.sqrt(n1**2 - n2**2); #Numerical aperture for optical fibre\nNA = math.ceil(NA*10**4)/10**4; #rounding off the value of NA to 4 decimals\n#As sin(theta_a) = sqrt(n1^2 - n2^2), solving for theta_a\ntheta_a = math.asin(math.sqrt(n1**2 - n2**2)); #Half of acceptance angle of optical fibre(rad)\ntheta_a = theta_a*57.2957795; #Half of acceptance angle of optical fibre(degrees)\ntheta_accp = 2*theta_a; #Acceptance angle of optical fibre(degrees)\ntheta_accp = math.ceil(theta_accp*10**2)/10**2; #rounding off the value of theta_accp to 2 decimals\nDelta = (n1 - n2)/n1; #Relative refractive index difference\nDelta = math.ceil(Delta*10**4)/10**4; #rounding off the value of Delta to 4 decimals\n\n#Result\nprint \"Numerical aperture for optical fibre is\", NA\nprint \"The acceptance angle of optical fibre is\",theta_accp, \"degrees\"\nprint \"Relative refractive index difference is\", Delta\n",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "Numerical aperture for optical fibre is 0.3775\nThe acceptance angle of optical fibre is 44.36 degrees\nRelative refractive index difference is 0.0345\n"
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example number 12.3, Page number 271"
},
{
"cell_type": "code",
"collapsed": false,
"input": "#To calculate the numerical aperture and acceptance angle\n\n#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nn1 = 1.55; #Refractive index of fibre core\nn2 = 1.53; #Refractive index of fibre cladding\nn0 = 1.3; #Refractive index of medium\n\n#Calculation\nNA = math.sqrt(n1**2 - n2**2); #Numerical aperture for optical fibre\nNA = math.ceil(NA*10**4)/10**4; #rounding off the value of NA to 4 decimals\n#n0*sin(theta_a) = sqrt(n1^2 - n2^2) = NA, solving for theta_a\ntheta_a = math.asin(math.sqrt(n1**2 - n2**2)/n0); #Half of acceptance angle of optical fibre(rad)\ntheta_a = theta_a*57.2957795; #Half of acceptance angle of optical fibre(degrees)\ntheta_accp = 2*theta_a; #Acceptance angle of optical fibre(degrees)\n\n#Result\nprint \"Numerical aperture for step index fibre is\",NA\nprint \"The acceptance angle of step index fibre is\",int(theta_accp), \"degrees\"\n",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "Numerical aperture for step index fibre is 0.2482\nThe acceptance angle of step index fibre is 22 degrees\n"
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example number 12.4, Page number 271 Theoritical proof"
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": "Example number 12.5, Page number 272"
},
{
"cell_type": "code",
"collapsed": false,
"input": "#To calculate the numerical aperture and acceptance angle\n\n#importing modules\nimport math\nfrom __future__ import division\n\n#Variable declaration\nalpha = 2; #Power loss through optical fibre(dB/km)\nP_in = 500; #Poer input of optical fibre(micro-watt)\nz = 10; #Length of the optical fibre(km)\n\n#Calculation\n#As alpha = 10/z*log10(P_in/P_out), solving for P_out\nP_out = P_in/10**(alpha*z/10); #Output power in fibre optic communication(micro-Watt)\n\n#Result\nprint \"The output power in fibre optic communication is\",P_out, \"micro-Watt\"",
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": "The output power in fibre optic communication is 5.0 micro-Watt\n"
}
],
"prompt_number": 6
},
{
"cell_type": "code",
"collapsed": false,
"input": "",
"language": "python",
"metadata": {},
"outputs": []
}
],
"metadata": {}
}
]
}
|
