光纤激光相干合成中倾斜和锁相同时控制的实验研究

光纤激光的相干合成是获得高能量密度、高光束质量激光输出的有效方法之一。在相干合成中，各个单元光束的倾斜波前畸变和活塞相位误差对合成的效果具有重要影响。搭建了两路光纤激光相干合成系统，利用光纤自适应准直器和相位调制器对相干合成中倾斜波前畸变和活塞相位误差进行校正。实验系统以高速相机采集的光斑数据作为评价依据，通过计算机程序进行控制，控制算法为随机并行梯度下降算法。在倾斜和锁相控制前，合成光斑的条纹对比度为0.03，桶中功率为8.03；在倾斜和锁相控制后，合成光斑的条纹对比度达到了0.59，桶中功率达到了32.89，说明实验中倾斜和锁相控制显著提高了相干合成的效果。

Experimental research of tilt-tip wavefront and phase-locking control in fiber lasers coherent beam combining

Coherent beam combining of fiber lasers is an very effective way to arrange high energy intensity and high beam quality laser. The tilt-tip wavefront aberrations and phase differences of each beamlet's have significant impacts on coherent beam combining. A coherent beam combining system of two fiber lasers was set up. In the experiment, adaptive fiber optics collimator and phase modulator were introduced to realize tilt-tip and phase control. The metric function came from the laser spot data acquired by high-speed camera, the control method was SPGD algorithm and the whole control was carried out by a computer. The contrast of combined spot is 0.03 and power in bucket is 8.03 before tilt-tip and phase-locking control, after tilt-tip and phase-locking control the contrast is 0.59 and power in bucket is 32.89, which means the control makes obvious improvement in coherent beam combining.