DISTRIBUTED RESONANT RING FIBER FILTER

摘要

Disclosed is a fiber optic filter that includes a central core (19), a ring core (20) concentric with the central core (19), an inner cladding region (21) of refractive index ni, and a cladding layer (22) of refractive index nc surrounding the ring core (20). The maximum refractive index n1 of the central core (19) and the maximum refractive index n2 of the ring core (20), are greater than nc and n1. At least at one wavelengths, power transfers between the two cores at (19 and 20). At least a portion of the filter (10) is wound around a reel (18) which determines the attenuation.