Manufacturing method for optical fiber grating

摘要

The present invention is a manufacturing method for an optical fiber grating which can decrease the light intensity at the bottom wavelength in the reflection or transmission spectrum to be sufficiently small. This method is comprised of a grating creation step and a phase adjustment step. The grating creation step is a step of creating a plurality of grating sections with different Bragg wavelengths arrayed in series in the longitudinal direction of this optical fiber, sandwiching the phase adjustment sections on an optical fiber made of a material which induces a light induced refractive index change phenomena. The phase adjustment step is a step of adjusting the light intensity at the bottom wavelength in the reflection or transmission spectrum of this optical fiber grating by irradiating the ultraviolet light only to the phase adjustment section while monitoring the transmittance or reflectance spectrum of the optical fiber grating after the grating step.