The influence of Mg and Ca atoms on the optical breakdown threshold of a nonlinear ZnGeP2 crystal at a wavelength of 2.097 mm is studied. An impurity was introduced using diffusion doping; the material was sputtered onto a ZnGeP2 substrate, followed by annealing in vacuum at a temperature of 750 °C for 200 hours. It is shown that the introduction of Mg into a single crystal increases the optical breakdown threshold by 31%. When ZnGeP2 is doped with Ca atoms, the opposite trend is observed. It is suggested that due to the creation of additional channels for energy dissipation of radiative and fast non-radiative relaxation processes through impurity energy levels, the optical breakdown threshold changes, which requires experimental confirmation.
optical breakdown, ZnGeP2, nonlinear crystal, diffusion doping, impurity atom, thermal diffusion
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