Efficient Nd:YVO4-KGW intracavity Raman lasers with linear and folded fundamental laser cavities

Abstract

The efficient Nd:YVO4/KGW continuous-wave (CW) intracavity Raman lasers in linear and folded cavities were demonstrated. The coupled cavity scheme was utilized to control the beam sizes in the laser crystal and Raman crystal, to alleviate the thermal issues and enhance the Raman gain. With the 1064 nm fundamental laser polarized along Nm axis of the Np-cut KGW crystal, 6.63 W of linear cavity and 9.33 W of folded cavity Stokes output at 1177.3 nm were obtained under an incident laser diode pump power of 36.65 W, with an optical efficiency of 18.1% and 25.5%, respectively. Our results show that the compact intracavity Raman laser is capable of generating multi-watt CW output efficiently by proper cavity arrangement. 10-watt level Raman output can be realized in the V-shaped cavity through parameter design. In contrast, the folded cavity scheme is more favorable for higher Stokes output power as well as efficiency compared with the linear cavity scheme because of its better mode matching.