Question

In graded index optical fibre refractive index of core is __________ and refractive index of cladding is __________ respectively.​

Answer 1

Explanation:

The core and cladding have different refractive indices, the core have a refractive index of n1, and the cladding have a refractive index of n2.

Refractive index n1 of core is defined as;

n1 = $\frac{c}{v}$        

c (3×10⁸ $\frac{m}{s}$) = speed of light in vacuum

v = speed of in the core.

Maximum size of angle must be smaller than 21°, in order to have total internal reflection at the core-cladding interface.