Abstract
Fiber laser is now widely recognized as the most reliable high average power, high brightness source.
However, the huge nonlinearities due to its small mode area and long interaction length make high
peak-power/high energy radiation so difficult. For peak-power/energy scaling, spatial beam combining,
in which multiple fiber lasers are phase-locked and their beams are combined, is the key architecture and
is extensively investigated in the world. We have been exploring phase-locked multicore fiber lasers and
are focusing here. A pioneering beam combining architecture based on reinforcement learning is also introduced.
Another approach, temporal beam combining, has also recently been extensively investigated
by researchers. Temporally separated pulses, with each peak power below the nonlinearity limit of fiber
laser/amplifier, are stacked coherently and can form one giant pulse with a higher peak power. In this
paper our recent results are mainly presented and the subjects and future prospects will be discussed.
