Coherent combining of multiple beams with multi-dithering technique: 100KHz closed-loop compensation demonstration

We demonstrate the coherent combining of three beams with a phase-locking controller using VLSI multi-dithering technique. Three fiber-coupled phase shifters are used to compensate phase distortions in the beam propagation path. The highest dither frequency in our system is ~70MHz. The achieved closed-loop compensation bandwidth of three beamlets is up to 100KHz.