Optical amplifier manufacture

摘要

A construction of gain tilt exhibiting optical amplifier that incorporates a gain flattening filter also includes a neutral density filter the value of whose attenuation is adjustable after assembly of the components of the amplifier. This neutral density filter is constructed by the performance of a succession of localised re-fusion operations at a localised region of an optical fiber. By this means the attenuation is increased to a desired value that provides the amplifier with optimised gain flattening at some predetermined value of amplifier external gain.