The surface laser-induced damage threshold (LIDT) of ${{\rm BaGa}_4}{{\rm Se}_7}$ and ${{\rm BaGa}_2}{{\rm GeSe}_6}$ nonlinear crystals was studied at 2091 nm. Both yellow and dark yellow phases of ${{\rm BaGa}_4}{{\rm Se}_7}$ were investigated. The Ho:YAG laser generating nanosecond pulses at 2 kHz, 5 kHz, and 10 kHz was used as a radiation source. The R-on-1 procedure was applied to determine the 0% probability damage threshold. The LIDT of the dark yellow phase of ${{\rm BaGa}_4}{{\rm Se}_7}$ without cleavage planes is very close to the ${{\rm BaGa}_2}{{\rm GeSe}_6}$ LIDT and exceeds by ca. 30% the LIDT of the yellow phase of ${{\rm BaGa}_4}{{\rm Se}_7}$ at 2 and 5 kHz.

中文翻译：

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纳米秒状态下2091 nm处非线性晶体BaGa ₄ Se ₇和BaGa ₂ GeSe _6的激光损伤阈值

$ {{\ rm BaGa} _4} {{\ rm Se} _7} $和$ {{\ rm BaGa} _2} {{\ rm GeSe} _6} $非线性晶体的表面激光诱导损伤阈值（LIDT）在2091 nm处进行了研究。研究了$ {{\ rm BaGa} _4} {{\ rm Se} _7} $的黄色和深黄色相。产生2kHz，5kHz和10kHz纳秒级脉冲的Ho：YAG激光器用作辐射源。应用R-on-1程序确定0％概率损坏阈值。没有解理平面的$ {{\ rm BaGa} _4} {{\ rm Se} _7} $暗黄色相的LIDT非常接近$ {{\ rm BaGa} _2} {{\ rm GeSe} _6 } $ LIDT，并超出约。$ {{\ rm BaGa} _4} {{\ rm Se} _7} $黄色相位在2 kHz和5 kHz时的LIDT为30％。