Coherent combining of a large-scale fiber laser array over 2.1km in turbulence based on a beam conformal projection system

We demonstrated a beam conformal projection system for coherent combining of large-scale lasers over 2.1km in turbulence 20 m above the ground, using the basic modules of a 19-element fiber phased array combined with coarse pointing by a gimbal mount. After coarse pointing and aberration corrections, the metrics (reflected light) of the combined beams from a basic module were best increased by 13.4 times, suggesting that our system promises the great effect of coherent combining under long-distance turbulence. Moreover, we tentatively realized coherent combining of two basic modules (38 lasers), which is the largest number of elements in a fiber laser coherent beam combination outdoors, to the best of our knowledge, with the metrics of combined beams increased by about 29 times. 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement