Polarization self-selection in passive phasing of four fiber amplifiers with an all-optical feedback loop is demonstrated. The polarization extinction ratio (PER) of the combined beam is increased, and the polarized direction is selected with the use of a polarization-maintaining (PM) isolator and some non-PM components. The best visibility of the interference patterns is observed at 95.2% and in the largest increment in the PER of the combined beam up to 7.4 dB. Results show that all PM components are unnecessary in the coherent beam combination with an all-optical feedback loop, whereas non-PM components have good potential to achieve high output power.
© 2012 Optical Society of America
Lasers and Laser Optics
Original Manuscript: June 19, 2012
Revised Manuscript: August 20, 2012
Manuscript Accepted: August 22, 2012
Published: September 14, 2012
Houkang Liu, Bing He, Jun Zhou, Chi Liu, Jingxing Dong, Yunrong Wei, and Qihong Lou, "Polarization self-selection in a coherent beam combination system with an all-optical feedback loop," Appl. Opt. 51, 6544-6548 (2012)