The optical properties of the nonlinear crystals BaGa4S7, BaGa2GeS6 and Ba2Ga8GeS16 were examined. The study covers transparency and tuning range for pumps at 1.064, 1.5, 1.85 and 2.09 μm, as well as the laser-induced damage threshold (LIDT) measured at ~2 μm with a 1 kHz repetition rate using the R-on-1 method. The study has demonstrated that the crystals exhibit a high LIDT of around 5.8–6.4 J/cm2. The combination of a high damage threshold and a broad transparency range of up to 12 μm suggests that sulfur-containing barium chalcogenide crystals hold promise for the development of widely tunable high-energy pulsed radiation sources for various applications, such as medical laser surgery and ablation.
Boyko et al. (Mon,) studied this question.