First-Stokes and second-Stokes multi-wavelength continuous-wave operation in Nd:YVO4/BaWO4 Raman laser under in-band pumping

A continuous-wave Nd:YVO4/BaWO4 Raman laser generating simultaneous multi-wavelength first-Stokes and second-Stokes emissions is demonstrated for the first time, to the best of our knowledge. Investigations concerning different pump spot sizes and crystal lengths were conducted to improve the thermal effect and pump absorption. Three first-Stokes lasers at 1103.6, 1175.9, and 1180.7 nm and two second-Stokes lasers at 1145.7 and 1228.9 nm are obtained simultaneously using the Raman shifts of 925 cm-1 and 332 cm-1 in BaWO4 and 890 cm-1 in YVO4. At the incident pump power of 23.1 W, 1.24 W maximum Raman output power is achieved,corresponding to an optical conversion efficiency of 5.4%. We also present a theoretical analysis of the competition between different Stokes lines.