6: Fiber Optics

Example number 6.1, Page number 160

In [5]:
#importing modules
import math
from __future__ import division

#Variable declaration
n1 = 1.5;      #refractive index of core
n2 = 1.0;      #refractive index of cladding

#Calculation
thetac = math.asin(n2/n1);      #critical angle(radian)
thetac = thetac*180/math.pi;        #critical angle(degrees)
thetac = math.ceil(thetac*10**2)/10**2;   #rounding off to 2 decimals

#Result
print "critical angle is",thetac,"degrees"

critical angle is 41.82 degrees

Example number 6.2, Page number 160

In [8]:
#importing modules
import math
from __future__ import division

#Variable declaration
n1 = 1.5;         #refractive index of core
n2 = 1.47;      #refractive index of cladding

#Calculation
thetac = math.asin(n2/n1);      #critical angle(radian)
thetac = thetac*180/math.pi;        #critical angle(degrees)
thetac = math.ceil(thetac*10**2)/10**2;   #rounding off to 2 decimals
NA = math.sqrt(n1**2-n2**2);           #numerical aperture of fiber
NA = math.ceil(NA*10)/10;   #rounding off to 1 decimal
thetaa = math.asin(NA);        #acceptance angle(radian)
thetaa = thetaa*180/math.pi;        #acceptance angle(degrees)
thetaa = math.ceil(thetaa*10**2)/10**2;   #rounding off to 2 decimals

#Result
print "critical angle is",thetac,"degrees"
print "numerical aperture of fiber is",NA
print "acceptance angle is",thetaa,"degrees"

critical angle is 78.53 degrees
numerical aperture of fiber is 0.3
acceptance angle is 17.46 degrees