A model was proposed for the kinetics of photo-induced defects and for photo-refractivity in germanosilicate fibers. It was based upon the existence of short-lived high-energy fluctuations which produced transient traps for carriers that released their energy and enhanced defect creation. The enhancement of photo-refractivity by the presence of H was explained in terms of 2 mechanisms that involved an increase in the number of weak bonds and the stabilization of the created defects. Analytical solutions were found, in certain cases, that explained experimental results reasonably well.

I.Abdulhalim: Applied Physics Letters, 1995, 66[24], 3248-50