Question

how to calculate Delta on fiber if I just have N1 and N2

can you tell what formula we use

Answer 1

'followed is the c program for calculation of ''Determine the numerical aperture and acceptance angle'''

import math

#Variable declaration

n1 = 1.55 #core refractive index

n2 = 1.51 #cladding refractive index

#Calculation

delta = (n1-n2)/n1

NA = 2*math.sqrt(delta)

theta_m = math.degrees(math.asin(NA))

#Result

print "Numerical aperture =",round(NA,4)

print "Acceptance angle =",round(theta_m,2),"degrees"

print "\nCalculation mistakes in textbook. Hence, the answers differ."

Numerical aperture = 0.3213

Acceptance angle = 18.74 degrees