SELF-ORGANIZED COHERENCE IN FIBER LASER ARRAYS BY MUTUAL INJECTION LOCKING

Self-organized coherent laser array seems to be a promising method for coherent combining fiber lasers. Phase locking is realized by mutual energy injection, without any active phase stabilization, requirement of the fiber length or the output power for individual lasers. In this paper, a novel self-organized coherent combination configuration of an array of fiber lasers has been demonstrated. Mutual injection locking and coherent combining of three and four individual erbium-doped fiber lasers have been reported. The fiber lasers are mutually injected by couplers. Under free running state, the far field beam profile is a simple intensity superposition as incoherent beams, under mutual injection locking, good coherence has been obtained in the far field of the fiber laser arrays. This scheme is quite easy to implement and can be extended to combine more beams.