Refractive Index Contrast

Refractive index contrast, in an optical fiber, is a measure of the relative difference in refractive index of the core and cladding. Refractive index contrast, Δ, is given by Δ = (n₁2- n₂2)/(2n₁2), where n₁ is the maximum refractive index in the core and n₂ is the refractive index of the homogeneous cladding.