Study of Refractive Index Change in Ge-Doped Fibers with Vacuum Ultraviolet Light Irradiation

Abstract

We determined that refractive index change of Ge-doped silica can be induced by vacuum ultraviolet (VUV) light irradiation from Xe 2 Ã , Kr 2 Ã , and Ar 2 Ã excimer lamps using fabricated fiber Bragg grating (FBG) in the core of the hydrogen-loaded fiber as the material. It was found that irradiation with light from Xe 2 Ã and Kr 2 Ã excimer lamps can change the refractive index in the core and irradiation with light from Ar 2 Ã excimer lamps cannot. The change in refractive index under 146 nm light irradiation was greater than that under 172 nm light irradiation. The change in refractive index induced by irradiation with VUV light can be maintained up to approximately 130 C.