Non-linear effects in chalcogenide glasses

Femtosecond filamentation of 800 nm laser pulses in the conditions of strong two-photon absorption was first directly observed in As4Ge30S66chalcogenide glass. In this paper we also present the experimental results on laser self-written waveguides in arsenic-germanium-sulfide glasses. In contrast, there was no filamentation and spectrum widening in stoichiometric As2S3glass. It was shown that nonlinear figure of merit was as high as 0.52 and only 0.04 in glassy As4Ge30S66and As2S3, respectively.