Optimization for coherent combined vortex fiber array with phase correction

The main factors limiting the long-distance application of vortex beam are the low receiving power and the wavefront phase distortion caused by atmosphere turbulence. Coherent beam combining (CBC) technology is an effective way to generating high power vortex beams. However, most common coherent combined vortex (CCV) fiber array is currently based on a single-ring structure with limited output power enhancement. In this paper, a dual-ring fiber array is developed to achieve higher output power and improved stochastic-parallel-gradient-descent (SPGD) correction accuracy. To improve SPGD correction speed, cross-grouping method is used. The results show that CCV beam in dual-ring structure can maintain good intensity distribution and mode distribution after SPGD correction.