power balance is necessary to icf, including the energy balance and pulse shape uniformity at the target . 90 percent of the output energy of " sg-ii " comes from its double-pass coaxial array main amplifiers, and pulse shape distortion caused by gain saturation also occurs mostly in there . therefore precise control of gain performance of the main amplifiers by avm ( angular variable mirror ) is the key to the precise power balance of " shenguang-ii " “神光?”装置90的激光能量由同轴双程主放大器提供,同时增益饱和效应产生脉冲波形畸变也主要发生在主放大器阶段,因此应用组合式角变反镜(avm,angularvariablemirror)独立精密控制主放大器各路的增益性能是实现“神光?”装置精密化功率平衡的关键。