Generation of the second harmonic of CO2 laser pulses in a ZnGeP2 crystal

Efficient second harmonic generation has been achieved from CO₂ laser pulses in a ZnGeP₂ single crystal. The influence of the repetition frequency and instability of the parameters of the pump light on the second harmonic generation and on the threshold for surface damage was studied. The effect of spatial nonuniformity of the crystal on the second-harmonic conversion efficiency was also studied.