当前, 基于多光束相干合成的激光相控阵技术面临着实际湍流环境下远距离传输的应用需求和挑战, 需同时校正系统内部光源噪声和外部动态湍流像差, 并解决远距离传输光延迟和系统规模增大导致的有效带宽急剧下降的问题。现有的技术手段如目标在回路技术和延迟SPGD算法无法应对湍流带来的动态倾斜像差, 而这一点对在远场目标处获得高质量相干合成光束至关重要。文中介绍了中国科学院光电技术研究所在多孔径激光传输控制技术上的最新研究进展, 新技术实现了对光纤阵列激光出射光束倾斜像差的并行和高效校正, 并提出了基于主动波前测量的光纤激光阵列外部像差预补偿校正的方法, 为光纤激光相控阵技术的实际大气传输应用打下基础。

Laser phased array technique on coherent combining of multiple beams faces challenges when applied in propagation through the long-range atmosphere. Aberrations in such transmission systems include turbulence-induced dynamic aberrations located at the path from the fiber laser array to the target, besides the inherent phase errors like phase noises and tip/tilt errors. Effective bandwidth for eliminating such aberrations is limited by the optical transmission delay and the increment of the array scale. Existing techniques, e.g., target-in-the-loop and delayed stochastic parallel gradient descent, are difficult to deal with the fast-changing turbulence-induced tip/tilt aberrations. But correcting these aberrations is critical for obtaining combined laser beams on the target with the best beam quality. In this paper, research progress of multi-aperture laser transceiving control for beam combining applications in IOE, CAS was presented. This method provided efficient ways to achieve tip/tilt control for the beam coupling from space to fiber and the outgoing laser beams in the beam combining applications. Correction of the aberrations outside the fiber laser array based on active multi-aperture wavefront sensing of the fiber laser array was proposed. These novel techniques presented here would promote the application of laser phased array technique in atmospheric propagation.