We present a model with which to calculate the index increase induced in standard single-mode fiber by hydrogen loading. Also, we propose that the dominant products of reaction in UV-written hydrogenated standard communication fibers are GeE′ and Si-OH. Based on the above models, we calculate the Bragg wavelength shifts that are due to hydrogen diffusion out of the fiber gratings. The relative effective index change that is due to hydrogen dissolved in fiber can be as much as 6 × 10<sup>-4</sup> if standard telecom fiber is hydrogen loaded with a concentration of ∼1.44 mol.%. Theoretical results agree with experimental results.
© 2000 Optical Society of America
(050.2770) Diffraction and gratings : Gratings
(060.0060) Fiber optics and optical communications : Fiber optics and optical communications
(060.2340) Fiber optics and optical communications : Fiber optics components
(230.1480) Optical devices : Bragg reflectors
L. B. Fu, G. Tan, W. J. Xu, H. L. An, X. M. Cui, X. Z. Lin, and H. D. Liu, "Ultraviolet-initiated reactions of H2 with germanosilicate fibers and H2 concentration dependence of the Bragg wavelength of a fiber grating," Opt. Lett. 25, 527-529 (2000)