Investigation of the Process of Optical Damage of ZnGeP2 Crystals Using Digital Holography

Influence of the Characteristics of Multilayer Interference Antireflection Coatings Based on Nb, Si, and Al Oxides on the Laser-Induced Damage Threshold of ZnGeP2 Single Crystal

“…These studies revealed a significant difference in the value of the LIDT of the ZGP crystal at wavelengths of 1064 nm and 2100 nm [10]. A dynamic visualization of the breakdown process by laser radiation at a wavelength of 2100 nm in the ZGP volume showed that an avalanche-like increase in temperature occurs in the forming track inside the nonlinear optical element [11]. An increase in the ZGP breakdown threshold reported in [12] with a decrease in the pump pulse duration "testifies in favor of the thermal nature of breakdown for nanosecond pulses due to anomalous infrared absorption".…”

“…In this regard, the potential for the practical use of high-power parametric oscillators in the mid-IR range while pumping by radiation in the wavelength range of ~2.1 µm is associated with the need to determine technological factors affecting the laser-induced damage threshold (LIDT). The problem of ZGP optical breakdown by laser radiation at wavelengths from 1.064 µm to 10 µm has been discussed in several previously published works [10][11][12][13][14][15][16]. These studies revealed a significant difference in the value of the LIDT of the ZGP crystal at wavelengths of 1064 nm and 2100 nm [10].…”

The Influence of the Angstrom-scale Roughness on the Laser-induced Damage Threshold of the ZnGeP2 Single Crystal

“…In this regard, the potential for the practical use of the OPO data of the mid-IR range is associated with the need to improve the methods for processing of the working surfaces of crystals to increase their LIDT. The problem of ZGP optical breakdown by laser radiation at wavelengths from 1.064 μm to 10 μm is devoted to several published earlier articles [11][12][13][14][15][16][17][18]. These articles have revealed a significant difference in the magnitude of the LIDT of the ZGP crystal at the wavelengths of 1.064 μm and 2.1 μm [11].…”

“…These articles have revealed a significant difference in the magnitude of the LIDT of the ZGP crystal at the wavelengths of 1.064 μm and 2.1 μm [11]. The dynamic visualization of the breakdown process with laser radiation at a wavelength of 2.1 μm in the volume of ZGP showed that an avalanche-shaped temperature increase occurs within the nonlinearoptical element [12]. An increase in the ZGP breakdown threshold with a decrease in the duration of the pump radiation pulses is "indicated in favor of the thermal nature of the breakdown for nanosecond pulses due to abnormal infrared absorption."…”

Application of Infrared Digital Holography for Characterization of Inhomogeneities and Voluminous Defects of Single Crystals on the Example of ZnGeP2

“…We have already published some results of works in this direction. Thus, for example, in [10] the method of digital holography was used to investigate the process of optical damage of a single crystal. In [11], it was proposed to use the digital holography method to visualize the internal inhomogeneities of the nonlinear ZnGeP 2 crystal, and the feasibility was demonstrated to evaluate shapes and typical sizes of defects.…”