Compact, efficient and power-ratio tunable orthogonally polarized Nd:YVO4 laser with coaxial diode-end-pumping configuration

Orthogonally polarized lasers (OPLs) play important roles in the application fields of precision measurement, imaging, etc. Compared with the traditional inefficient gas lasers, all-solid-state OPLs has significant advantages in output power and feasible frequency difference. In this paper, a compact, efficient and power-ratio tunable OPL with single-wavelength emission at 1064 nm is proposed using two Nd:YVO4 crystals and a coaxial diode-end-pumping configuration. The parameters of the pump source and gain media were optimized to realized high efficiency with balanced output power, as well as large tuning range of power ratio between two polarization components. Under the pump power of 13.29 W, the output power reached 2.92 W at each polarization, corresponding to the optical–optical conversion efficiency of 43.94%. The anisotropic thermal effects at two polarizations was also investigated, which was the basis of cavity design for higher output power and better beam quality. In the experiment, an overall beam quality factor (M2) of 2.23 and the RMS power instability of 1.19% was realized for the OPL.