By using a novel mutual injection technique, phase-locking and coherent combining of two high power all-fiber lasers are realized and experimentally demonstrated by Wei Zhao’ research team. Steady interference strips with high visibility of 46% are observed. The coherent combined 407 W CW output power with a power-combining efficiency of up to 98% is obtained. The laser array works well with excellent stability. In the long time of high power operation no thermal distortions or damages are observed. The experiment results reveal that the proposed technique can be used to further scaleup the coherent combined output power of high power fiber lasers.

（Original research article: Optics Communications 283(11):2390-239, https://doi.org/ 10.1016/j.optcom.2010.02.004）