Goodno Gregory D, Weiss S Benjamin
Northrop Grumman Aerospace Systems, One Space Park, R1-1184D, Redondo Beach, California 90278, USA.
Opt Express. 2012 Jul 2;20(14):14945-53. doi: 10.1364/OE.20.014945.
We demonstrate a novel closed-loop approach for high-precision co-alignment of laser beams in an actively phase-locked, coherently combined fiber laser array. The approach ensures interferometric precision by optically transducing beam-to-beam pointing errors into phase errors on a single detector, which are subsequently nulled by duplication of closed-loop phasing controls. Using this approach, beams from five coherent fiber tips were simultaneously phase-locked and position-locked with sub-micron accuracy. Spatial filtering of the sensed light is shown to extend the control range over multiple beam diameters by recovering spatial coherence despite the lack of far-field beam overlap.
我们展示了一种用于在主动锁相、相干合成光纤激光器阵列中对激光束进行高精度共对准的新型闭环方法。该方法通过将光束到光束的指向误差光学转换为单个探测器上的相位误差来确保干涉测量精度，随后通过重复闭环相位控制将这些误差消除。使用这种方法，来自五个相干光纤尖端的光束同时以亚微米精度进行锁相和位置锁定。结果表明，尽管缺乏远场光束重叠，但通过恢复空间相干性，对传感光进行空间滤波可将控制范围扩展到多个光束直径。
