OPTICAL FIBER GRATING FILTER FOR REDUCING WAVELENGTH SHIFT AND METHOD FOR MANUFACTURING THE SAME

摘要

PURPOSE: An optical fiber grating filter for reducing a wavelength shift and a method for manufacturing the same are provided to easily design the filter and to obtain a high reliability in the manufacturing and design of the grating since the shift of the central frequency becomes small during the manufacturing of the grating. CONSTITUTION: A method for manufacturing an optical fiber grating filter includes the steps of: positioning an inner cladding having a predetermined thickness between an optical fiber core(4) and an external cladding(18); doping a photosensitive material to cause the refractive index to be changed by reacting the ultraviolet ray with the optical fiber core(4) and the inner cladding(16) in such a way that the periodic change of the refractive index due to the optical fiber grating occurs at the core(4) and the inner cladding(16) simultaneously; generating the mode coupling between the core mode and the cladding mode; and reducing the shift of the central frequency occurring the mode coupling for the illumination amount of the ultraviolet ray.