Comparative study of laser performance for two a -cut Tm:YLF slab crystals with their c-axes mutually orthogonal

Abstract The laser performance of two a -cut Tm:YLF slab crystals with c -axis along the x -direction and y- direction is compared. These two lasers are compared under identical pump conditions in a continuous wave regime. A maximum output power of 135 W at 1908 nm Tm:YLF laser with two slab crystals is obtained, corresponding to an optical-to-optical efficiency of 43.3% and a slope efficiency of 50.6% with the respect to the absorbed pump power of 312 W. At the output power of 110 W, the M 2 factors in the x -direction and y -direction are 293 and 1.74, respectively. The shape of the output light is a rectangular spot. The polarization of the output light is σ -polarized.