Laser damage of the nonlinear crystals CdSiP2 and ZnGeP2 studied with nanosecond pulses at 1064 and 2090 nm

CdSiP2 (CSP) is a very promising nonlinear crystal for the mid-infrared spectral range with a nonlinear coefficient slightly larger than that of ZnGeP2 (ZGP). In contrast to ZGP, CSP is phase-matchable and can be employed in 1.064-mu m pumped optical parametric oscillators (OPOs) without two-photon absorption. Although low damage resistivity has been reported in such initial OPO tests of CSP, no reliable data on the damage threshold of uncoated CSP exists. In this work, we compare the damage resistivity of uncoated CSP with ZGP at two wavelengths, 2.09 mu m (1 kHz, 21 ns) and 1.064 mu m (100 Hz, 8 ns). (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)