Bragg gratings have been UV written in UV hypersensitized standard fibers through exposure of a phase mask to KrF laser light. On the other hand, UV hypersensitized preform plates and fibers have been postexposed in conditions similar to those used to write the gratings. Vacuum-UV and IR absorption spectroscopy has been carried out with a view of monitoring the kinetics of formation (or bleaching) of defect-associated bands. The fluence per pulse F<sub>i</sub> was the parameter of the exposures. The dependence of the refractive index changes on fluence per pulse points to a two-photon absorption mechanism for Bragg grating inscription. This dependence is correlated to the one for the GeE′ defect and OH species-related absorption bands and discussed within the framework of a two-step model.
© 2006 Optical Society of America
Fiber Optics and Optical Communications
Original Manuscript: January 13, 2006
Manuscript Accepted: February 20, 2006
Matthieu Lancry, Pierre Niay, Marc Douay, and Bertrand Poumellec, "Mechanisms of Bragg grating formation in UV hypersensitized standard germanosilicate fibers with KrF laser light," J. Opt. Soc. Am. B 23, 1556-1564 (2006)