建立了包括非热稳定热力学模型、光学传输模型、能量转换模型及非稳腔模型的综合理论分析平台。理论分析得到以下主要结论：谐振腔长度变化对光束质量及光光效率的影响不大，对于给定的增益，激光最佳效率和光束质量分别对应不同的非稳腔放大率。提出非稳腔腔内相位板补偿介质静态畸变提高光束质量的技术措施，并开展实验验证，光束质量由补偿前的5.48倍衍射极限提升到补偿后的2.46倍，输出功率为12.1 kW。

An integrated theoretical analytic platform is developed, which consisted of the thermodynamic model, beam transformation model, energy transition model and active unstable resonator model. The main conclusion of theory analysis is that: the beam-quality and optical-optical efficiency are weakly impacted by the length of resonator on fixed gain; the optimal efficiency and beam-quality are different corresponding to magnification for unstable resonator. The experiment of phase plate with passive resonator compensation is accomplished, the beam quality is improved from 5.48 times of diffraction limit to 2.46, with the output power of 12.1 kW.