在增益导引的作用下,未采用任何补偿措施,主振荡功率放大(MOPA)激光器的输出光光束质量得到改善。综合考虑热效应、增益导引效应、增益饱和效应后,在MOPA系统中建立了一种新的激光放大模型,并进行了数值计算,模拟结果与已报道的实验结果符合较好。另外,计算结果表明填充因子和抽运光功率是影响输出激光光束质量的重要因素,而热效应与增益导引效应是其深层原因,这对进一步利用增益导引效应改善光束质量具有指导意义。 Without gaining any compensation, the quality of the output light beam from the main oscillator power amplifier (MOPA) laser is improved with gain guidance. Considering the thermal effect, gain guidance effect and gain saturation effect, a new model of laser amplification in MOPA system is established and numerically calculated. The simulation results are in good agreement with the reported experimental results. In addition, the calculation results show that the fill factor and pump power are the important factors affecting the output laser beam quality. The thermal effect and gain steering effect are the underlying reasons, which is instructive for further utilizing the gain steering effect to improve the beam quality.