Visualization of Volumetric Defects in a ZnGeP 2 Single-Crystal by Digital Holography Method Using Strontium Vapor Laser Radiation

A method for visualization of volumetric defects in a ZnGeP2 single-crystal by digital holography method using strontium vapor laser radiation is proposed. The possibility of obtaining a volume distribution of defects with dimensions of ≥15–20 μm and their identification in a crystal is shown. The identification in a ZnGeP2 single-crystal of such volumetric defects as growth bands and needle inclusions of zinc phosphides is carried out. Processing of holographic data has resulted in determination of the periodicity of the formation of growth bands, and evaluation of physical causes leading to the appearance of growth bands with a period of ~10–20 µm, ~25–90 µm, and ~200 µm.