Abstract

Coherent beam combination of ten fiber arrays using a stochastic parallel gradient descent (SPGD) algorithm is demonstrated. A high speed phase controller has been designed and manufactured based on the SPGD algorithm and a field programmable gate array (FPGA). The signal processing speed of the FPGA circuit is 50 MHz and its iteration rate is more than 200 kHz. Experimental investigation on coherent beam combination of 10 fiber laser beams is successfully demonstrated, with imposing additional phase disturbances to mimic the phase noises in the high power fiber amplifiers. The combining efficiency is about 96.4% and 92.6% without/with additional phase distortion, corresponding to the RMS phase error of λ/35 and λ/23.

© 2015 Optical Society of America

Coherent beam combination of three two-tone fiber amplifiers using stochastic parallel gradient descent algorithm

Pu Zhou, Yanxing Ma, Xiaolin Wang, Haotong Ma, Xiaojun Xu, and Zejin Liu
Opt. Lett. 34(19) 2939-2941 (2009)

Bandwidth and stability of the stochastic parallel gradient descent algorithm for phase control in coherent beam combination

Matts Björck, Markus Henriksson, and Lars Sjökvist
Appl. Opt. 60(15) 4366-4374 (2021)

Modal decomposition of an incoherent combined laser beam based on the combination of residual networks and a stochastic parallel gradient descent algorithm

Fan Chen
Appl. Opt. 61(14) 4120-4131 (2022)

Distributed active phase-locking of an all-fiber structured laser array by a stochastic parallel gradient descent (SPGD) algorithm

Hongxiang Chang, Rongtao Su, Jinhu Long, Qi Chang, Pengfei Ma, Yanxing Ma, and Pu Zhou
Opt. Express 30(2) 1089-1098 (2022)

Adaptive stochastic parallel gradient descent approach for efficient fiber coupling

Qintao Hu, Liangli Zhen, Yao Mao, Shiwei Zhu, Xi Zhou, and Guozhong Zhou
Opt. Express 28(9) 13141-13154 (2020)