Locking of ultra-high peak pulses in harmonically mode-locked erbium-doped fiber ring lasers

We report a new mode-locking phenomenon in which ultrahigh peak or "giant" pulse trains have certain pulse drops in an active mode-locked fiber ring laser. Generated pulse trains have properties similar to a return-to-zero format with a clear pedestal, with pulse trains circulating in the ring of peak power reaching 575 mW, which is about ten times higher than the actual peak output power. The temporal pulse trains and their optical spectra are described and discussed. It is believed that this is due to the interaction between copropagating pulses in the ring and the supermode competition. (c) 2005 Society of Photo-Optical Instrumentation Engineers.