泵浦光的离轴对激光器性能影响

利用光纤耦合激光二极管端面泵浦固体激光器，研究了在近阈值条件下，泵浦光偏离振荡光谐振腔轴线距离的变化对激光器输出模式、阈值功率、斜效率和光束质量的影响．实验结果表明，当泵浦光相对振荡光谐振腔轴线的偏离量增加时，激光振荡阈值、斜效率和光束质量因子将增大；激光输出模式从低阶向高阶厄米-高斯模转变，并且在相同的泵浦光偏离位置下，随着泵浦光电流的增大，晶体热效应显著，模式竞争加剧，会出现高阶向低阶厄米-高斯模的转变．

An experimental study of the effect of off-axis pumping on laser characteristics

This paper deals with the law of the threshold, oscillating modes, slope efficiency and the beam quality varying with the pumping position under the condition of the off-axis pumping. The results prove that the threshold, the slope efficiency and the factor of the beam quality become higher and the laser mode changes from the high order to the low order Hermite-Gaussian mode as the Δx departs from the axis. At the same pumping position, the laser mode changes from the high order to the low order Hermite-Gaussian mode because of the heat domino effect becoming prominent as the LD current increase.