Answer to Question #70808 in Optics for jagat

Question

Consider a parabolic-index multimode fiber with n1= 1.46, ∆ = 0.01, operating at 850 nm with an LED of spectral width 20 nm. For such a fiber find the intermodal dispersion and total dispersion with its bit rate.(material dispersion = 1.7ns/Km.

Answer 1

The intermodal dispersion is given by,
τ_i=(n_1 L∆)/c (1)
Of (1) τ_i=(1.46×1000×0.01)/(3×〖10〗^8 )=48.7ns , which is usually written as 48.7 ns⁄km
The total dispersion is given by,
τ=√(τ_i^2+τ_m^2 ) (2), where τi is the intermodal dispersion, τm is the material dispersion
Of (2) τ=48.72 ns⁄km
Answer:
The intermodal dispersion: 48.7 ns⁄km
The intermodal dispersion: 48.72 ns⁄km