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{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Ch-2, Optical Fibers & its types"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 2.1 ; page 146"
]
},
{
"cell_type": "code",
"collapsed": true,
"input": [
"from __future__ import division\n",
"#Given data :\n",
"n1=1.40 #refractive index\n",
"delta=1 #relative refractive index difference in %\n",
"#Formula : n2/n1=1-delta\n",
"n2=n1*(1-delta/100) #refractive index(unitless)\n",
"print \"Refractive index of cladding is\",n2"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Refractive index of cladding is 1.386\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 2.2 ; page 149"
]
},
{
"cell_type": "code",
"collapsed": true,
"input": [
"from __future__ import division\n",
"from numpy import sin, arcsin, pi\n",
"#Given data :\n",
"fi_o=22 #in Degree\n",
"delta=3 #relative refractive index difference in %\n",
"#Part (a) :\n",
"#Formula : NA=sin(fi_o).....(max)\n",
"NA=sin(fi_o*pi/180) #Numerical Aperture(Unitless)\n",
"print \"Numerical Aperture : \",round(NA,2)\n",
"#Part (b) :\n",
"#Formula : n2/n1=1-delta\n",
"#Let say, n2/n1=n2byn1\n",
"n2byn1=(1-delta/100) #refractive index(unitless)\n",
"#Formula : sin(fi_C)=n2/n1 \n",
"fi_c=arcsin(n2byn1) #in degree\n",
"print \"Critical Angle at core cladding interface is\",round(fi_c,2),\"Degree\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Numerical Aperture : 0.37\n",
"Critical Angle at core cladding interface is 1.33 Degree\n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 2.3; page 156"
]
},
{
"cell_type": "code",
"collapsed": true,
"input": [
"from __future__ import division\n",
"from numpy import sqrt\n",
"#Given data :\n",
"delta=0.45 #relative refractive index difference in %\n",
"fi_o=0.115 #in Radian\n",
"c=3*10**8 #speed of light in m/s\n",
"#Formula : NA=sin(fi_o).....(max)\n",
"NA=sin(fi_o) #Numerical Aperture(Unitless)\n",
"#Formula : NA=n1*sqrt(2*delta)\n",
"n1=NA/sqrt(2*delta/100) #unitless\n",
"#Formula : n1=c/v \n",
"v=c/n1 #in m/s\n",
"print \"Speed of light in fibre core is \",round(v,2),\" m/s\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Speed of light in fibre core is 248028935.21 m/s\n"
]
}
],
"prompt_number": 12
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 2.4; page 157"
]
},
{
"cell_type": "code",
"collapsed": true,
"input": [
"from __future__ import division\n",
"from numpy import sqrt, pi\n",
"#Given data :\n",
"n1=1.5 #Unitless\n",
"delta=1 #relative refractive index difference in %\n",
"lamda=1.3 #in um\n",
"N=1100 #No. of modes\n",
"#Formula : v=2*%pi*a*n1*NA/lambda \n",
"#NA=sqrt(2*delta)\n",
"#v=sqrt(2*N)\n",
"a=(sqrt(2*N)*lamda)/(2*pi*n1*sqrt(2*delta/100)) #Normalized frequency\n",
"d=2*a # um\n",
"print \"Diameter of the fiber core is\",round(d,2),\"um\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Diameter of the fiber core is 91.5 um\n"
]
}
],
"prompt_number": 15
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 2.5; page 159"
]
},
{
"cell_type": "code",
"collapsed": true,
"input": [
"from __future__ import division\n",
"from numpy import sin, pi\n",
"#Given data :\n",
"\n",
"n1=1.52 #unitless\n",
"fi_o=8 #in Degree\n",
"#Formula : sin(fi_o)=n1*sqrt(2*delta)\n",
"delta=(sin(fi_o*pi/180)/n1)**2/2 #Relative refractive index\n",
"delta*=100 # in %\n",
"print \"The value of relative refractive index difference is \",round(delta,2),\"%\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The value of relative refractive index difference is 0.42 %\n"
]
}
],
"prompt_number": 17
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 2.6; page 162"
]
},
{
"cell_type": "code",
"collapsed": true,
"input": [
"from __future__ import division\n",
"from numpy import pi, sqrt\n",
"#Given data :\n",
"N=700 #No. of modes\n",
"d=30 #in um\n",
"a=d/2 #in um\n",
"NA=0.62 #Numerical Aperture\n",
"#Formula : v=2*sqrt(N) and v=2*%pi*a*NA/lambda\n",
"lamda=2*pi*a*NA/(2*sqrt(N)) #in um\n",
"print \"Wavelength of light propagating in fibre is\",round(lamda,2),\" micro meter\""
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Wavelength of light propagating in fibre is 1.1 micro meter\n"
]
}
],
"prompt_number": 18
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 2.7;page 165"
]
},
{
"cell_type": "code",
"collapsed": true,
"input": [
"from __future__ import division\n",
"from numpy import pi, sqrt\n",
"#Given data :\n",
"n1=1.5 #unitless\n",
"alfa=2 #characteristic index profile\n",
"d=40 #in um\n",
"a=d/2 #in um\n",
"#Part (a) :\n",
"lamda=1.3 #in um\n",
"delta=1 \n",
"#Formula : v=2*%pi*a*NA/lambda=2*%pi*a*(n1*sqrt(2*delta))/lambda\n",
"v=2*pi*a*(n1*sqrt(2*delta/100))/lamda #Unitless\n",
"print \"Normalized Frequency for single mode transmission : \",round(v,2) \n",
"#Part (b) :\n",
"#Formula : N=(alfa/alfa+2)*(v**2/2)\n",
"N=(alfa/(alfa+2))*(v**2/2) #No. of guided modes\n",
"print \"No. of guided modes propagating in the fibre is %d\" %N"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Normalized Frequency for single mode transmission : 20.51\n",
"No. of guided modes propagating in the fibre is 105"
]
},
{
"output_type": "stream",
"stream": "stdout",
"text": [
"\n"
]
}
],
"prompt_number": 20
}
],
"metadata": {}
}
]
}