Principle and numerical demonstration of high power all-fiber coherent beam combination based on self-imaging effect in a square core fiber
Yuefang Yan, Yu Liu, Haoyu Zhang, Yue Li, Yuwei Li, Xi Feng, Donglin Yan, Jianjun Wang, Honghuan Lin, Feng Jing, Wenhui Huang, Rumao Tao
Abstract
The self-imaging effect in a square core fiber has been investigated, and an integrated all-fiber combiner has been proposed based on a large mode area double clad fiber, which can be employed to construct high power coherent beam combining sources in the all-fiber format. The influence of various parameters on beam quality ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:msup> <mml:mrow> <mml:mi mathvariant="italic">M</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> ) and efficiency of the all-fiber coherent beam combiner has been studied numerically, which reveals that the near diffraction-limited laser beam can be achieved. A principle demonstration of the self-imaging effect has been carried out experimentally in a square core fiber, which proves the feasibility of beam combining with the square fiber, and that it is a promising way to develop high power coherent beam combination sources.