Simulation of the transient thermal effect for end-pumped Nd: YAG crystals operation at the repetition rate of 1 kHz

The laser diode (LD) end-pumped solid-state lasers with excellent output characteristics are extensively used in many fields. The thermal effects of the laser crystal are one of the key factors preventing the laser from achieving high-quality output. In this paper, the thermal effects of a laser at 1 kHz repetition rate were explored by developing a three-dimensional thermal model of an end-quasi-continuous waves (QCW) LD pumped Nd: YAG crystal. Considering the radial and axial heat conduction of the laser crystal, the transient temperature field within the crystal was numerically calculated using a seven-point finite difference method (FDM). The transient thermal effects of the composite crystal were compared with those of the non-composite crystal. The effects of different parameters on the transient thermal effects of the composite crystal were discussed in detail. This simulation work is believed to guide the design of thermally stable cavities for lasers operating at muti-kHz to attain favorable laser characteristics.