We present a full-scale numerical study of thermally induced optical aberrations on the primary mirror of a beam director telescope. In particular, we investigate high-power laser-induced deformations, resulting monochromatic aberrations, and their effects on imaging and laser focusing performance of primary telescope mirrors in shared aperture beam director systems. As a practical example, we consider a system based on 6 × 4 kW single-mode high-power laser sources and a primary mirror having a 500 mm circular clear aperture. A detailed comparison of the monochromatic aberrations and their implications on the optical performance is provided for borosilicate and Zerodur® substrates having identical reflective coatings for potential laser beam director applications. Our analyses show that high-power lasers can be efficiently directed with negligible imaging degradation using athermal substrates (i.e., Zerodur®) with high reflective coatings (>99.9 % ) for primary mirrors. On the other hand, substrates with a relatively higher coefficient of thermal expansion (i.e., borosilicate) can only be used effectively under a strictly controlled ambient temperature.

中文翻译：

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光束导向镜上的高功率激光引起的光学像差

我们对光束导向器望远镜的主镜上的热致光学像差进行了全面的数值研究。特别是，我们研究了高功率激光引起的变形、由此产生的单色像差，以及它们对共享孔径光束导向系统中主望远镜反射镜的成像和激光聚焦性能的影响。作为一个实际例子，我们考虑一个基于 6 × 4 kW 单模高功率激光源和一个具有 500 mm 圆形通光孔径的主镜的系统。对于具有相同反射涂层的硼硅酸盐和 Zerodur® 基材，为潜在的激光束导向器应用提供了单色像差及其对光学性能影响的详细比较。我们的分析表明，使用具有高反射涂层 (>99.9%) 的无热基材（即 Zerodur®）作为主镜，可以有效地引导高功率激光，而成像退化可忽略不计。另一方面，热膨胀系数相对较高的基材（即硼硅酸盐）只有在严格控制的环境温度下才能有效使用。