A graded-index fiber has a core with parabolic refractive index profile of diameter of 30μm, NA=0.2, λ=1μm. Estimate the normalised frequency.

A graded-index fiber has a core with parabolic refractive index profi

1.	A graded-index fiber has a core with parabolic refractive index profile of diameter of 30μm, NA=0.2, λ=1μm. Estimate the normalised frequency.
A.	19.32
B.	18.84
C.	16.28
D.	17.12
Answer» C. 16.28