Question

Calculate the numerical aperture and acceptance angle for an optical diver having core of refractive index1.55 and cladding of refractive index1.50 respectively

Answer 1

The refractive index of core, n₁ = 1.55

and the refractive index of cladding , n₂ = 1.50

Numerical aperture (NA) =$\sqrt{n_1^2-n_2^2}=\sqrt{1.55^2-1.50^2}=\sqrt{0.1525}=0.39$

Acceptance angle =sin^-1(NA) = sin^-1(0.39) = 23^o