Coherent combining of two pulsed fibre lasers in phase modulated mutually coupled fibre laser array

A scalable architecture for coherent combining of pulsed fibre lasers is reported. Stable synchronous and phase-locked pulsed fibre laser beams are generated in a phase modulated mutually coupled fibre laser array. The mechanism for generating a pulsed laser is different from previous Q-switching, modelocking or pump modulation methods. Two pulsed fibre lasers are coherently combined with 0.48 µJ pulse energy at the repetition rate of 115 kHz. The repetition rate can be controlled by adjusting the pump current. The combining efficiency of the two pulsed fibre lasers reaches 90% and the fringe contrast is larger than 40%.