Abstract

Volume Bragg gratings (VBGs) are optical devices exhibiting a periodic refractive index structure typically inside bulk glass. Due to their characteristics they can be employed for a wide range of applications such as beam combiners for e.g. fiber or solid state lasers, frequency narrower and stabilizers for semiconductor lasers for e.g. pumping laser materials with narrow absorption bands, as well as pulse compressors in case of chirped VBGs. Typically, VBGs are fabricated in photo-thermo-refractive glass by exposure with an interference pattern of an UV-laser ([1]). Alternatively, ultrashort laser pulses can be used to inscribe permanent refractive index changes in a multitude of glasses - photosensitive and non-photosensitive. Here, we employ this direct inscription technique using femtosecond pulses and a phase mask to realize VBGs in fused silica for the stabilization of laser diodes ([2,3]).

© 2015 IEEE