In the existing deformable mirror (DM)-based adaptive interferometers for freeform surfaces test, the departure coverage and the DM surface monitoring load are contradictory to each other. We reported an adaptive ring-cavity compensator (ARCC) based freeform surface interferometer. With the multiple cyclic reflections of the beam in the ARRC, the departure coverage is enlarged to four times of the stroke of one DM. With only one DM, the ARCC achieves the coverage comparable to dual-DMs, without any incremental DM monitoring load and decoupling operation. The interferometer coverage is thus doubled at a relatively low cost. The freeform surface measurement and the DM surface monitoring are performed with a rotatable polaroid for gating, without any other auxiliary devices. Validated experiments are presented.

中文翻译：

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带自适应环形腔补偿器的自由曲面干涉测量

在现有的基于变形镜（DM）的用于自由曲面测试的自适应干涉仪中，离场覆盖率和DM表面监控负载彼此矛盾。我们报告了一种基于自适应环形腔补偿器（ARCC）的自由曲面干涉仪。通过ARRC中光束的多次循环反射，离场覆盖范围扩大到一个DM行程的四倍。仅使用一个DM，ARCC就可以实现与双DM相当的覆盖范围，而无需任何增量DM监视负载和去耦操作。因此，以相对较低的成本将干涉仪的覆盖范围增加了一倍。自由曲面测量和DM表面监控使用可旋转的宝丽来进行选通，而无需任何其他辅助设备。提出了经过验证的实验。