战术激光武器聚焦发射特性计算研究

Computational Research on Focused Emission Characteristics of Tactical Laser Weapons

依据激光光束理论，基于共轴卡塞格伦望远镜系统和典型激光光束参数，利用数学软件Mathcadl4，对战术激光武器聚焦发射特性进行了计算研究，以为实际系统设计提供参考。分析发现：①最大聚焦距离为有限值，且随几何放大倍率和主、次镜焦距的增大而增大，随入射光束发散性的增大而减小；②聚焦距离可调并伴随着聚焦光斑大小和远场发散角的变化，可定义”光束准直”和”功率聚焦”两种调焦模式，其中，前者对应大腰斑、小光束发散角，而后者对应小腰斑、大光束发散角，更有利于获得高的到靶激光功率密度，但光束的聚焦距离需要与目标距离严格一致；③不同的光学参数可实现同样的聚焦距离，但几何放大倍率越大，或在同样几何放大倍率下，主、次镜的曲率半径越大，聚焦光斑越小。

The characteristics of focused emission of tactical laser weapons were investigated computationally u- sing the software Mathcadl4 according to laser beam theory, based on the co-axial cassegrain telescope system and typical laser beam parameters, so as to provide references for the design of practical systems. The maximum focusing distance is found to be finite and to increase with the geometric optical magnification and the focal lengths of the main and sub mirrors, and to decrease with the divergence of the incident laser beam. Besides, it is indicated that the focusing distance is adjustable while coupled with the variation of the focused beam size and the far-field divergence, and two focus-adjustment modes may be defined as ＂beam collimation＂ and ＂power fo- cusing＂, of which, the former mode corresponds to relatively large beam waist sizes and small beam divergence, while the latter mode corresponds to smaller beam waist sizes and larger beam divergence, giving rise to higher on-target laser power density, with the beam required to focus accurately on the target in terms of distance. Fur- ther analysis reveals that same focusing distances may be obtained using different optical parameters, while the focused beam size decreases with the increase of the geometric optical magnification, or of the radius of curvature of the main and sub mirrors for fixed geometric optical magnifications.