High-energy pulses from all-PM ultra-long Yb-fiber laser mode-locked with quasi-synchronous pumping

We explore, for the first time, mode-locking capabilities and frontiers of a quasi-synchronous pumping technique implemented in an all-polarization-maintaining (all-PM) kilometer-long Yb-fiber laser. This technically simple approach to synchronous pumping relies on sine-wave modulation of pump power at a frequency slightly detuned from the laser cavity inter-mode frequency or its multiple. In combination with the scaled-up all-PM-fiber cavity,...