Research on the thermal effect and laser resonator of diode-pumped thin-slab Tm:YAP lasers

A diode-pumped Tm:YAP crystal model was built and analyzed to present an analytical solution of the heat equation for a thin-slab geometry crystal. Using Matlab, the temperature distributions of Tm:YAP crystal at different plane were calculated and shown under different pumping and cooling condition. The calculation results show that the temperature distribution is greatly dependent on the thickness of the Tm:YAP crystal and characteristics of pump light, such as pump power and spot size. The thermal focal length produced by temperature gradient was also calculated and the results show that the thermal lens effect was enhanced with the increase of the pump power density while the size and doping concentration of Tm:YAP crystal is assumed stationary. And at last, a stable laser resonator is designed and analyzed according to the calculation result of thermal lens.