Theoretical Study on Phase Locking of Arrays of Mutually-Injected Fiber Lasers

Phase locking of arrays of mutually-injected fiber lasers is investigated theoretically. The phase-locked states of this array are analytically discussed. It is revealed that phase locking of this array is affected by the transfer characteristic of the coupler used for mutual injection. Arrays fabricated with two kinds of couplers (i.e., 1 × 3 coupler and the compound coupler built with two 1 × 2 couplers) are studied. It is found that the compound coupler is more suitable for phase locking of the array. The relationship between the phase-locked states and the number of elementary lasers of the array is also studied.