研究一种具备校正活塞和倾斜像差能力的自适应锁相光纤激光阵列, 利用多相位屏法对其在不同强度湍流大气中的传输性能进行数值计算, 引入光束质量因子BPF对湍流大气的影响进行定量分析。当湍流强度较弱(折射率结构常数为C2n=1×10－15 m－2/3, 传输距离为10 km, 相干长度为4.3 cm)时, 湍流大气对激光阵列传输的影响较小, 光强分布与在真空中传输效果基本一致。当湍流强度较强(折射率结构常数分别为C2n=5×10－15 m－2/3和1×10－14 m－2/3, 相干长度分别为1.6 cm和1 cm)时, 自适应锁相光纤激光阵列的BPF分别为理想情形下的86%和70%; 对应的未校正活塞像差和倾斜像差的光纤激光阵列传输至远场处的BPF值分别为理想情形下的55%和38%。计算结果表明, 由于校正了活塞和倾斜像差, 在较强湍流大气中传输时, 自适应锁相光纤激光阵列能够显著提高远场光强的能量集中度。

An adaptive phase-locked fiber laser array with piston and tip-tilt error correction capability is investigated. The propagation performance of the adaptive phase-locked fiber laser array in different turbulent atmosphere is numerically studied by using multiple phase screen method. BPF is introduced as beam quality factor to study the effect of turbulence atmosphere on the propagation performance quantitatively. The influence is neglectable and the field intensity distribution remains unchanged compared to free space when the intensity of turbulence is weak (C2n=1×10－15 m－2/3, propagation distance z=10 km, coherence length=4.3 cm). The BPF value becomes 86% and 70% of the idea case when C2n=5×10－15 m－2/3 and 1×10－14 m－2/3 (corresponding coherence length are 1.6 cm and 1 cm, respectively), while the BPF value for the fiber laser array propagating in the same atmosphere without correcting piston and tip-tilt error are 55% and 38% of the idea case. The calculation results reveal that the energy centrality can be advanced evidently by the adaptive phase-locked fiber laser array.