Problem 11: Fiber optics are an important part of our modern internet. In these
ID: 1400785 • Letter: P
Question
Problem 11: Fiber optics are an important part of our modern internet. In these fibers, two different glasses are used to confine the light by total internal reflection at the critical angle for the interface between the core (n core = 1.502) and the cladding (n cladding =1.447) Randomized Variables n score = 1.502 n cladding = 1.447 Part (a) Numerically, what is the largest angle (in degrees) a ray will make with respect to the interface of the fiber theta max and still experience total internal reflection? Part (b) Suppose you wanted the largest angle at which total internal reflection occurred to be theta'c = 5 degrees. What index of refraction does the cladding need if the core is unchanged?Explanation / Answer
given,
refractive index of core n_core = 1.502
refractive index of cladding n_cladding = 1.447
by the condition of total internal reflection
n_core * sin(critical angle) = n_cladding * sin(90)
1.502 * sin(critical angle) = 1.447 * sin(90)
critical angle = 74.45 degree
theta_max = 90 - 74.45
theta_max = 15.55 degree