High-precision active synchronization control of high-power, tiled-aperture coherent beam combining

We propose and demonstrate a high-precision active control technique for tiled-aperture coherent beam combining suitable for high-power laser pulses. The method is a hybrid structure based on the near-field interference fringe technique and single-crystal balanced optical cross-correlation, which enables the active loop to exhibit high accuracy, wide dynamic range, and good capacity for resisting energy disturbance. In the proof-of-principle experiment, we realized an adjustable beam combining bandwidth of approximately 100 Hz (limited by the speed of the piezoelectric transducer) and root-mean-square deviation of approximately λ/51 for two beam channels with a combining efficiency of 93%.