采用自行设计的基于大规模可编程门阵列(FPGA)结构的控制电路, 实现了4路光纤激光的多抖动法相干合成。对大气湍流和机械振动引起的相位噪声进行了有效补偿, 使远场光斑条纹对比度由开环时的0.21提高到了闭环时的0.93, 闭环时远场特定孔径内的能量较开环时提高了3.3倍。该方法还对人为抖动光纤引起的较高频率噪声具有很好的抑制作用, 系统闭环后, 远场光斑条纹对比度可达到0.72。

Coherent beam combining of four fiber laser beams with multi-dithering based on field programmable gate array(FPGA) control module was demonstrated. When the phase control system is in close loop, the phase errors between the beams induced by atmospheric turbulence and mechanical vibrations are compensated and the contrast of the far-field coherent combined beam profile is improved to 0.93 from 0.21 in the open loop, and the power in the given area is 3.3 times higher. Even if the fibers are dithered, the contrast of far-field beam profile is still held at 0.72.