Producing regenerated gratings in hydrogen-loaded single mode fiber by heat treatment

Abstract

Fiber Bragg grating (FBG) is a passive optical fiber component with the refractive index modulated along the fiber length and has been widely applied in fiber sensing systems. High-temperature stable fiber gratings are promising for uses at high temperature and receive extensive attentions. In this paper, FBGs were inscribed in hydrogen loaded standard single mode fibers with 248 nm excimer laser, and regenerated gratings were obtained through heat treatment. The center wavelength of the regenerated FBG has a good linearity with temperature, and the reflectivity of the regenerated FBG can almost keep unchanged at 800 °C.