OPTICAL FIBERS HAVING CORE REGIONS WITH REDUCED ALPHA PROFILES

摘要

An optical fiber includes a core portion having a radius r_C and a graded refractive index profile Δ_C having an alpha value greater than or equal to 1 and less than or equal to 8. The core portion includes a silica-based glass and a down-dopant, where a concentration of the down-dopant is graded such that the concentration of the down-dopant decreases from the radius r_C towards the center of the core portion. The optical fiber comprises a cladding portion surrounding the core portion and having a relative refractive index Δ_OC that is less than a maximum refractive index Δ_Cmax of the core portion.