We report a study of the effect of postgrowth treatment of ZnGeP₂ single crystals (low-temperature annealing, irradiation with fast electrons, polishing of working surfaces) and the conditions of exposure to repetitively pulsed laser radiation [wavelength (2091 or 1064 nm), pulse repetition rate, beam diameter, exposure time, sample temperature] on the laser-induced damage threshold (LIDT) of the surfaces of these crystals. It is found that thermal annealing of ZnGeP₂ single crystals and their irradiation with a flux of fast electrons, which increase the LIDT at a wavelength of λ = 1064 nm, do not lead to a change in this threshold at λ = 2091 nm. It is shown that ZnGeP₂ elements with lower optical losses in the spectral range 0.7 – 2.5 μm have a higher LIDT at λ = 2091 nm both immediately after fabrication and after postgrowth processing. An increase in the threshold energy density of laser radiation by a factor of 1.5 – 3 at λ = 2091 nm is revealed with a decrease in the crystal temperature from zero to –60 C. The fact of reversible photodarkening of the propagation channel of laser radiation in ZnGeP₂ in the predamage region of parameters is established by the method of digital holography.

我们报告了对 ZnGeP ₂单晶的后生长处理（低温退火、快速电子辐照、工作表面抛光）的影响以及暴露于重复脉冲激光辐射[波长（2091 或 1064 nm）的条件的研究，脉冲重复率、光束直径、曝光时间、样品温度]对这些晶体表面的激光损伤阈值 (LIDT) 的影响。发现 ZnGeP ₂单晶的热退火和它们用快电子通量的辐照增加了波长λ = 1064 nm 处的 LIDT，但不会导致该阈值在λ = 2091 nm 处发生变化。结果表明，ZnGeP ₂在 0.7 – 2.5 μm 光谱范围内具有较低光学损耗的元件在制造后和生长后处理后在λ = 2091 nm 处具有较高的 LIDT。在λ = 2091 nm 处，激光辐射的阈值能量密度增加了 1.5 – 3 倍，这表明晶体温度从零降低到 –60 C。激光辐射传播通道的可逆光暗化事实在ZnGeP ₂中的损伤前区域的参数是通过数字全息的方法建立的。