Multi-soliton formation in femtosecond degenerate optical parametric oscillators

Multi-soliton formation is observed theoretically and experimentally in femtosecond degenerate optical parametric oscillators (OPOs). We show that when the pulse energy of the pump source of a femtosecond OPO is increased to a certain level, the existing soliton will move towards the leading edge of pump pulses due to the enhanced nonlinear acceleration, and the undepleted pump energy will support the generation of more solitons. We have successfully observed the generation of double solitons and triple solitons in experimental demonstrations with the measured pulse characteristics agreeing well with the theoretical ones. The generation of multi-soliton sources may stimulate many novel applications, including data storage, telecommunication, and all-optical signal processing.