Optical filter fabrication method and apparatus, optical filter, fiber holder with spiral groove, and phase mask

摘要

An optical filter is manufactured by placing a photosensitive optical fiber (20) in a spiral arrangement on a fiber holder (10), preferably having a spiral groove (22) for holding the fiber, and exposing the fiber to ultraviolet light through a phase mask (12) having a spiral diffraction grating, forming an in-fiber Bragg grating. The fiber can be conveniently scanned by an ultraviolet beam as the fiber holder and phase mask turn on a rotating stage (14). The fiber can be compactly packaged between the fiber holder and a cover. The fiber holder and cover can be formed by coating a substrate with layers of polymer material, the spiral groove being formed by photolithographic patterning of one of the layers. <IMAGE>