Fiber laser based on 4-core Yb-doped fiber and multimode Bragg grating

摘要

We have realised and studied the fiber laser based on 4-core Yb-doped fiber and multimode Bragg grating as the input reflector. The lasing efficiency slope of 55% was measured. An investigation of the output emission has shown that the far field pattern constitutes an inteference picture. That allows us to conclude that the multimode Bragg grating provides phase locking of 4 lasers utilizing the different active cores. A coherant length of laser is longer than possible difference between optical ways of different active cores.