Optical fiber grating, optical fiber grating manufacturing method, and optical fiber grating manufacturing apparatus

Abstract

The invention provides a method and apparatus that precisely and efficiently improves the optical properties of an optical fiber grating. Preferably hydrogen loading processing, grating formation processing that forms a grating part by irradiation with ultraviolet light at a predetermined period, and preferably dehydrogenation, adjusting the optical properties by a suitable combination of uniform ultraviolet irradiation processing that irradiates the grating part as a whole with ultraviolet light and heat trimming processing, and finally heat aging is carried out.

1 . An optical fiber grating comprising a grating part having a periodic refractive index distribution due to irradiation of the optical fiber along the longitudinal direction by ultraviolet light at a predetermined period and a sample fiber having a constant refractive index, wherein the minimum refractive index of said grating part is larger than the refractive index of said sample fiber, and the variation of the smallest refractive index of said grating part is sufficiently smaller than the amount of change in the periodic refractive index.  
   
   
       2 . A manufacturing apparatus for an optical fiber grating providing an ultraviolet irradiating apparatus and a heating apparatus for adjusting the optical properties of the optical fiber grating.  
   
   
       3 . A manufacturing apparatus for an optical fiber grating according to claim  6  wherein a mechanism that implements said uniform ultraviolet irradiation processing and said heat trimming processing maintains a constant tension on the optical fiber.