In recent years, with the proposed master oscillator power-amplifier (MOPA) structure, the fiber laser coherent combining technology has broken the limit of the maximum output power of a single fiber, and realized the laser output with high brightness and improved beam quality, which will be one of the important directions of high power laser systems in the future. As a typical representative of multi-beam coherent combining methods, fiber laser array technology has also been continuously advanced. 

Tomorrow, the fiber laser array technology must face and address the challenge of long-distance transmission under atmospheric turbulence, and need to correct the aberrations through full-range transmission. But, the mature wavefront sensing method that has been used in traditional adaptive optics systems cannot be directly applied to the fiber laser coherent combining system. So it is necessary to develop a new form wavefront sensor that can be perfectly integrated with the fiber laser array. 

Li Xinyang’s team in Key Laboratory of Adaptive Optics, Chinese Academy of Sciences, proposed a fiber laser array aberration detection method based on fiber coupling. They simulated the process of recovering turbulence aberrations and conducted experiments of restoring static aberration using 7-element adaptive fiber optics collimator (AFOC) array. The numerical results showed that the proposed method can effectively recover the turbulent distorted wavefront, and there are different optimal restoration number of orders for the hexagonal array with different element. This technology is expected to be applied in systems such as laser array atmospheric transmission and turbulence correction. 

The research results were published in the recent Opto-electronic Engineering.

Paper link:http://www.oejournal.org/J/OEE/Article/Full/A180424000012/CN