Efficient Actively Q-Switched Nd:YAP/YVO4 Raman Laser Operation at 1195 nm

We investigate the first-Stokes operation of YVO4 crystal driven by an acousto-optic Q-switched Nd:YAP laser with X(ZZ)X Raman configuration. The fundamental wavelength laser operation by Nd:YAP crystal was at 1080 nm corresponding to the first-Stokes wavelength at 1195 nm based on the Raman shift of 890 cm−1 in a-cut YVO4 crystal. Under an incident pump power of 8 W and a pulse repetition frequency of 25 kHz, an average output power of 1.24 W and a pulse width of 2.9 ns were achieved with the conversion efficiency up to 15.5%. In the experiment, the weak Stokes at 1125 nm converted with a low wave-number Raman shift of 376 cm−1 was also detected.