Femtosecond laser induced damage on Ge-As-S chalcogenide glasses

The laser irradiation damage on Ge-As-S chalcogenide glasses was studied with 216-fs pulses with repetition rates (RRs) of 1 kHz-1 MHz at 1030 nm. The compositional dependence of the laser damage threshold was systematically investigated, and the damaged mechanisms corresponding to the irradiation pulses with different RRs were discussed. We found that the stoichiometric compositions have the best resistance to the optical damage irrespective of the RR. When the irradiation pulses operate at 1 kHz, the damage is mainly caused by avalanche ionization. In comparison, thermal accumulation becomes prominent as the RR exceeds 10 kHz and becomes a main factor in the damage when the RR is more than 100 kHz. The results could be helpful for composition choices and pumping scheme designs in nonlinear optics. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement