Growth and Characterizations of ZnGeP2 Crystal by a Vertical Bridgman Method

ZnGeP2 (ZGP) single crystal with size of 24 mm in diameter and 70 mm in length was grown by a modified vertical Bridgman (VB) method in a three-zone furnace. The crystal was annealed in ZnGeP2 powder at 600 °C for 500 h. X-ray diffraction (XRD), X-ray fluorescence (XRF) and Fourier transform infrared spectrophotometry (FTIR) were employed to characterize its properties. A ZGP optical parametric oscillator (ZGP-OPO) device was fabricated from the annealed sample. Laser experiment was carried out on the device. Tunable mid-infrared laser in the range of 3∼5 μm was realized on the ZGP-OPO pumped by 2.1 μm, 7 kHz laser. All the results indicate that our grown crystal is in good quality and can be used for nonlinear optical applications.