Indication of re-circulating catalyst in photosensitive reactions with H < inf > 2 < /inf > -saturated silica fibers

Abstract

The dynamics of Bragg grating growth in ultraviolet (UV)-sensitized, hydrogen saturated silica fibers were explained using a transient kinetic model. Three different types of fibers with an average core germanium concentration of 3.5, 5 and 10-mole % were used. Re-circulation of hydrogen, functioning as catalyst in the photosensitive reactions was responsible for the increase in the steady state value of the refractive index changes.