在惯性约束核聚变激光驱动装置中, 光路庞大复杂且元器件众多, 为保证激光系统正常运行需对光路进行精密调节。特别是装置中的多个4F系统, 需调整激光光路使其聚焦后对准焦平面滤波小孔中心, 以保证激光顺利通过并实现低通滤波作用。目前实际工程中采用凹透镜背光照明的方法判断光束是否准确过孔, 但该方法步骤繁琐且调整精度较低, 给实际光路调整带来了极大的不便。本文基于全息原理, 提出了一种简单高效的4F系统光路调整方法, 通过一特殊设计的分光照明衍射光学元件, 可一步实现激光聚焦过孔的判断与调整, 可有效解决现有4F系统光路调整的困难。

Numerous elements and huge laser system are existed in Inertial Confine Fusion driver (ICF). It is necessary to adjust light path accurately so as to ensure that the laser system can work normally. Expecially, the 4F system in ICF plays a role of low-pass filtering, so the purpose of adjusting is to make laser pass the center of filter hole in focus plane. Currently, the method in practical engineering is to use a concave lens for splitting light illumination to judge whether the beam pass the filter hole. However, the disadvantage of this method is tedious and low precision, which is inconvenient in actual adjusting. In this paper, a simple but effective way to adjust light path in 4F system is presented based on holography theory. With a specially designed diffractive optical element for splitting light illumination, judging and adjusting laser to pass the filter hole can be easily achieving. Thus, it can solve the difficulty of existing method.