Fiber laser transceiving and wavefront aberration mitigation with adaptive distributed aperture array for free-space optical communications.

Abstract

In this Letter, we propose and demonstrate efficient adaptive optics correction of a distributed 19-element fiber laser array for both receiving and transmission for the first time, to our best knowledge. Active beam coupling from space into polarization-maintaining fibers and all-fiber active cophasing beam combining with multiple-level fiber couplers are performed. Phase distortions distributed throughout the optical path from the simulated target to the receiving port are eliminated, and nearly ideal coherent combining is achieved in the far-field. Comprehensive reception efficiency is raised up to 52 times with the whole equivalent aperture of 152 mm and the far-field power-in-the-bucket metric up to 8.27 times. The optimal array element parameters for a given whole array aperture and turbulence intensity are analyzed.