Efficient Conversion from 1 μm to 2 μm by HGTR KTP Optical Parametric Oscillator at 10 KHz Repetition Rate
Kc Bahuguna, Swati Verma, Chitra, Vinod Kumar, N. S. Vasan, S. P. Gaba and S. S. Negi
An efficient conversion of 1 mm to 2 mm has been demonstrated using HGTR KTP crystal based OPO pumped by Q-switched Nd:YVO4 laser at 10 KHz repetition rate to pump a ZGP crystal to get infrared radiation. The near degenerate wavelengths generated are 2.098 mm and 2.161 mm. The performance of the OPO was investigated by changing the crystal temperature, cavity length and changing the output coupler reflectivity. Optimum output power from this OPO was obtained at 34 mm cavity length, at 70oC crystal temperature and at 80% output coupler reflectivity. Maximum output power of 7.5 W was obtained on incidence of 19.6 W pump power corresponding to 38.7% conversion efficiency. The peak output power obtained from the OPO was 127 kW. The measured values of the divergence of output beam were 3.7 mrad and 4.1 mrad in x and y directions, respectively.
Keywords: Nonlinear frequency conversion, Optical parametric oscillator, Nonlinear crystal, High gray track resistance KTP crystal, Laser, Nd:YVO4