Single-channel Q-switching in a system of coherently combined fiber lasers

We experimentally investigate passive interferometric coherent combining of two photonic crystal fiber laser channels within a common cavity, wherein only one channel is Q-switched. We demonstrate an average power of more than 20 W and the peak power of 97 kW with more than 98 % combining efficiency. The measured spectral bandwidth is 0.13 nm, and it does not change at different operation conditions. Our results show efficient imposing of temporal and spectral characteristics of the Q-switched channel on the free-running channel.