Beam phase-distortion correction in a high power laser based on the stochastic parallel gradient descent technique

The feasibility of the closed-loop adaptive optic system based on laser far-field information was experimentally demonstrated, which can significantly increase the working efficiency of the multi-beamline high power solid laser facility. A stochastic parallel gradient descent algorithm with mean-radius cost function was applied in the adaptive optics that was installed in one chosen beamline in the SG-III laser facility. The far-field diameter from a reference laser was corrected from about 275 to 100??m, very close to the ideal limit of 75??m. Multiple-wavefront correction can be performed with this far-field detection based adaptive optics system, and the experimental result validates the practicability of the proposed system in the multi-beamline high power solid laser facilities.