Gain and refractive index guiding effects on the mode formation in the solid state laser resonators

摘要

We have developed a three dimensional computer model of the combined guiding mechanism for the transverse mode formation in the end-pumped laser resonator. The finite difference beam propagation method is used to solve the nonlinear Schrodinger-type wave equation in the gain medium with combined guiding mechanism, i. e. the thermal induced refractive index guiding effect as well as the gain guiding effect. After establishing the pump absorption model of end-pumped YAG/Nd:YAG/YAG laser resonator, the temperature distribution in the gain medium is obtained by the numerical solving of the heat diffusion equation. The combined guiding effect is observed in the end-pumped Nd:YAG laser resonator; numerical results show that combined guiding mechanism dominates the transverse mode formation in high power end-pumped laser resonator.