In this paper, the composite Nd:YVO4 laser crystal is in-band pumped by a wavelength-locked laser diode at 878.9 nm, with the purpose of reducing thermal effects and improving pump absorption simultaneously. By using the YVO4 and BaWO4 crystals as Raman media, the influences of crystal properties, resonator structure and stability on the performance of continuous-wave intracavity Raman laser are investigated experimentally and theoretically. The results show that the resonator stability greatly affects laser performance due to the long cavity length of intracavity Raman laser. By choosing the Raman medium with high Raman gain, we can not only obtain higher Raman conversion efficiency, but also reduce the thermal effect to a certain extent. Furthermore, the smaller the curvature radius of the output mirror in the plano-concave cavity structure, the greater the power density of the fundamental laser in the Raman crystal is and the wider the dynamic stability region of the resonator, and hence the higher output power of the Raman laser can be achieved. Finally, by using 30-mm BaWO4 crystal as Raman medium, a highest Raman output of 3.02 W is obtained at a pump power of 25.1 W, corresponding to a diode-to-Stokes optical conversion efficiency of 12%.

Multi-wavelength continuous-wave self-Raman laser with an a-cut composite YVO4/Nd:YVO4/YVO4 crystal pumped by an 879-nm wavelength-locked laser diode is demonstrated for the first time. Multi-wavelength Raman lasers at 1168.4, 1176, 1178.7, and 1201.6 nm are achieved by the first Stokes shift of the multi-wavelength fundamental lasers at 1064, 1066.7, 1073.6, 1084, and 1085.6 nm with two Raman shifts of 890 and 816 cm−1. A maximum Raman output power of 2.56 W is achieved through the use of a 20-mm-long composite crystal, with a corresponding optical conversion efficiency of 9.8%. The polarization directions of different fundamental and Raman lasers are investigated and found to be orthogonal π and σ polarizations. These orthogonally polarized multi-wavelength lasers with small wavelength separation pave the way to the development of a potential laser source for application in spectral analysis, laser radar and THz generation.

In this paper, a continuous-wave all-solid-state Nd:YVO4 self-Raman laser in-band pumped by a wavelength-locked laser diode at 878.9 nm is theoretically investigated in detail. Considering the thermal lens effect in the laser crystal, cavity mode parameters are calculated for several output couplers with different radii of curvature, by employing the standard ABCD matrix approach and equivalent G parameter method. The influence of cavity structure on the output characteristic of the Raman laser is investigated by analyzing mode matching between the pump and the fundamental beams, as well as the fundamental intensities in the Raman crystal. This provides theoretical explanations for the experimental results, and based on the analysis above, laser cavity is optimized. Finally, a highest Raman output of 5.3 W is obtained at 1175 nm, corresponding to a diode-to-Stokes optical conversion efficiency of 20%.