Analytical solution of the thermal effects in a high-power slab Tm:YLF laser with dual-end pumping

Abstract

The thermal effects model of the anisotropic slab crystal was built based on the practical operation condition of the solid-state laser. A full analytical solution of the heat equation for an anisotropic cubic cross-section, solid-state crystal is presented. We can conclude that the analytical solution carries a very considerable reliability level when it was compared with the numerical solution and experimental measurements. The expressions that are reported here were applied to a slab Tm:YLF crystal, and the results showed that the thermal lens effect was enhanced with the increase of the pump power density. Thermal deformation produced by thermal lens effect plays a leading role in the Tm:YLF crystal at this time. When the product of crystal length and doping concentration was a constant value, the thermal focal length remained basically consistent. However, the slab laser crystal should have decreased doping concentration and a moderately increased crystal length in order to relieve the thermal effects.