公里级湍流大气环境下光纤激光高效相干合成

光纤激光阵列光束相干合成可在提升输出激光总功率的同时保持良好的光束质量，进而提升激光亮度，是激光技术领域的研究热点。目前光纤激光相干合成实验已在实验室内获得了大量、良好的验证，然而在真实湍流大气环境下的长距离传输实验却开展较少，相干合成技术对湍流大气引入的相位畸变的校正能力尚需实验验证。目标在回路技术是实现长距离湍流大气环境下阵列光束到靶相干合成的重要方案，是近年来国际上的重点研究方向。基于自适应光纤准直器阵列和共形发射系统，搭建了6路光纤激光目标在回路相干合成系统，成功校正了湍流大气带来的相位畸变，实现了公里级作用距离、湍流大气环境下阵列光束在目标表面的相干合成。

Efficient coherent beam combining of fiber laser array through km-scale turbulent atmosphere

Coherent beam combining (CBC) of fiber laser array can improve the total output laser power while maintaining good beam quality, thus improving the laser brightness. CBC of fiber laser array has been a research hotspot in the field of laser technology and has attracted much attention. At present, lots of CBC experiments have been successfully established and verified in the laboratory. However, there is few long distance propagation experiment carried out in real turbulent atmospheric environment. The ability of compensating the phase distortions introduced by the turbulent atmosphere still needs to be tested and verified experimentally. The target-in-the-loop technique is an important and useful method to realize the coherent combining of array beams at the target surface in a real long-distance turbulent atmospheric environment. CBC of fiber lasers based on target-in-the-loop technique becomes a key goal and an important research direction since it has been proposed. Based on the adaptive fiber collimator array and conformal projection system, a target-in-the-loop CBC system of six fiber amplifiers was established, which successfully compensated the phase distortions and realized CBC at the target surface through a kilometer-scale propagation distance with atmospheric turbulence.