Compact passively Q-switched KTA self-frequency doubled Raman laser with 671 cm−1 shift

Abstract

Compact yellow laser source based on KTA self-frequency-doubled Raman conversion was demonstrated. Cr4+:YAG bonded on Nd: YAG crystal was selected for passively Q-switched fundamental laser generation and making the system more compact. Both stimulated Raman scattering and frequency doubling were successfully realized in the same x-cut KTA crystal. Single wavelength laser at 573 nm was generated by frequency doubling of the first-Stokes at 1146 nm with the Raman shift of 671 cm−1. Under an incident pump power of 10.5 W, the average output power of 240 mW and conversion efficiency of 2.3% are obtained from the output coupler end of the laser setup. Frequency doubling generated towards the pump input end of the laser cavity was not collected. The pulse repetition frequency and pulse width are 11.6 kHz and 1.2 ns were detected at the incident pump power of 10.5 W. The narrow pulse width of this positively Q-switched yellow laser resulted in much higher peak power up to 17.2 kW.