Coherent beam combining of fiber lasers based on common ring cavity coupling configuration

To improve the combining efficiency, stability and expandability of passive selfadjusting coherent combining arrays of fiber lasers, a novel coherent beam combining scheme of fiber lasers is proposed based on a common ring coupled cavity and single mode fiber filtering. Multiple 2×2 fiber couplers are inserted into the resonators of component fiber lasers, respectively, and the remaining ports of the fiber couplers are connected with each other to form the common ring coupled cavity. All the fiber lasers can realize efficient mutual injection coupling through the common ring cavity, and therefore phase locking output can be achieved. The stability of phase locking among the emitting laser beams is improved by the single mode fiber filtering technique. Passive phase locking of three fibe