Photosensitization and photostabilization of laser-induced index changes in optical fibers

Improved understanding of the underlying fundamental mechanisms of the photosensitivity used to create index change within optical fibers can lead to substantial improvements in optimizing these changes for fiber grating writing. Recent work in unravelling and understanding photosensitization has lead to results which suggest that with an appropriate UV writing recipe one can achieve photostabilization of the gratings equivalent to sufficient thermal annealing of Bragg gratings to ensure stable operation over 25 years. In this paper those results and the mechanism of sensitization are reviewed. (C) 2000 Academic Press.