为了优化高功率固体激光装置波前补偿系统的设计方案, 基于构型验证装置开展了波前测试和补偿实验。实验结果显示, 虽然等效钕玻璃片数大大增加, 但由于主放采用了“U”型反转器技术, 扣除离焦量后的静态和动态波前与原型装置相比没有显著提高, 主要变化为离焦分量。若不采取任何补偿措施, 会影响激光在前级滤波器的顺利过孔, 造成近场缺光现象。实验中, 为保证激光在动态发射时顺利过孔, 采用了调节透镜的方式, 使激光在各级滤波小孔位置有合适的预留量。同时, 利用原型装置现有的小口径变形镜对扣除离焦后的像差进行补偿, 减小激光在末级滤波小孔位置的像差。综合上述两种方法, 成功解决了近场缺光的问题。针对未来高功率固体激光装置, 伴随着光束口径和等效钕玻璃片数的增加, 主放大器内的像差也会大幅度增加, 采用上述调节透镜的方式可能无法兼顾静态和动态两种状态下的通光问题, 需要在主放大系统内增加主动补偿措施, 为腔镜变形镜的应用提供了实验依据。

In order to optimize the design scheme of the wavefront control system in a high power solid-state laser facility, wavefront test and correction experiment are conducted on a verification facility. The results show that, although the equivalent number of Nd: glasses increases, the output static and dynamic wavefronts without defocus component is not largely raised for the application of U-turn beam reverser in the main amplifier. However, the defocus component visibly increases. And the laser is blocked at the pinhole of the spatial filter. The output near field of the main amplifier has sharp modulation and energy loss. In the experiment, the defocus component before each pinhole is adjusted in advance by moving the focal lens in the optical path. And the static wavefront without defocus component is corrected by the deformable mirror to reduce aberration at the pinhole of the last stage filter. Combining the two methods, sharp modulation and energy loss problem in near field is solved at single shot. Output wavefront of main amplifier in ICF driver will be larger with beam aperture and equivalent number of Nd: glasses increasing in the future. The scheme of the large deformable mirror at the location of cavity mirror will be an effective way to ensure beams passing through each pinhole.