Coherent beam combining of two W-level fiber amplifiers in turbulence atmospheric environment based on stochastic parallel gradient descent algorithm

摘要: We demonstrate coherent beam combining of two W-level fiber amplifiers based on stochastic parallel gradient descent (SPGD) algorithm at 8 m distance in a simulated turbulence atmospheric environment. A photodetector was used to get the optical intensity main-lobe from pinhole, and SPGD algorithm, phase controlling performed by digital signal processor. In order simulate environment, induced free space light path fans air-conditions lab. Experimental result shows that system performs well for long-time both with without simulating close-loop, efficiency as high 84.25% 84.85% were realized. Visibility increased near zero open-loop 0.432 0.505 close-loop residual error is controlled be less than λ/18. The probability energy encircled more 70% its ideal value 18.66 93.71% 14.80 92.49% when evolves close-loop.