Analysis on Power Scalability of Multicore Fiber Laser

Multicore fiber laser is a promising approach to get high-power laser beams while maintaining good beam quality. The in-phase complex amplitude distribution for regular multicore fiber lasers with different core numbers is calculated using FDTD method. It is shown that the in-phase turn out a bell-shape profile owing to different coupling intensity in different cores, the output power of the outside ring cores with decrease as the distance to the central core get larger. The total in-phase mode output power for regular multicore fiber lasers as a function of core numbers is obtained. The total output power of 61-core fiber laser is only 12 times of the central core in order to keep an in-phase mode, which brings a restriction to the power scalability of multicore fiber laser. The multicore fiber should be mode shaped to keep the in-phase mode a flat-shape profile. The in-phase mode can still be selected by using a Talbot cavity by numerical calculating, which show that the mode-shaped multicore fiber laser output power is of great promise to scale to a high-power level.