四程放大激光系统输出能量稳定性研究

 根据原型装置主放大系统组合式四程放大结构的特点，计算分析了放大过程中注入能量、放大增益及损耗的微小起伏对系统输出能量稳定性的影响。根据原型装置集成实验结果，分析了目前原型装置单路输出能量稳定性水平。研究结果表明：注入能量越大，其变化对输出能量影响越小；小信号增益系数对输出能量的影响明显大于注入能量；系统输出能量稳定性对腔内光学元件的透过率变化要求高于腔外光学元件。在3 ns基频光输出达标点处要使输出能量不稳定性控制在5%以内，注入能量起伏要低于10%，腔内放大片小信号增益系数起伏要低于1%，腔内光学系统损耗起伏要低于2%。

Output energy stability of the four-pass amplification system

In accordance with the built-up structure of the main amplifier in technical integration experiment line(TIL), the effects of the injected energy,amplifier gain and transmission on the output energy stability were calculated.Experimental results show that the greader the injected energy,the weaker the effect of the injeeted energy on the output energy.The effect of the small gain coefficient was greater than that of the injected energy.And the effect of the loss component tromsmission on the output energy stability in amplification cavity was more obvious than the effect on the output energy stability out of amplifuation cavity.The level of the output energy stability of TIL was analyzed according to the experimental data.For the 3 ns temporally flat pulse,to meet the requirement of output energy stability less than 5%,the allowable random variation of the injected energy is less than 10%,the amplifier gain is less than 1%,and the loss component transmission of the amplification cavity is less than 2%.