Conventional cavity alignment sensing uses multi-element photodiodes to sense the matching of a laser beam to the mode of a cavity. We present a new approach that uses a single-element photodiode combined with deformable mirrors to modulate orthogonal codes across distinct spatial regions of the laser wavefront. By decoding the photodiode signal it is possible to map the mode mismatch and produce error signals for feedback to the mirrors to optimize the coupling of the laser to the cavity. We characterise this sensing and control system experimentally and demonstrate closed-loop enhancement of cavity alignment and mode matching.

中文翻译：

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具有单个光电二极管和空间光调制的Fabry-Pérot腔自动模式匹配

传统的腔对准感测使用多元件光电二极管来感测激光束与腔模式的匹配。我们提出了一种新方法，该方法使用单元素光电二极管与可变形反射镜相结合，在激光波前的不同空间区域上调制正交代码。通过解码光电二极管信号，可以映射模式失配并产生误差信号以反馈至反射镜，以优化激光器与腔体的耦合。我们通过实验表征该传感和控制系统，并演示腔对准和模式匹配的闭环增强。