Coherence study of DSR-like pulses in passively mode-locked fiber lasers

Dissipative soliton resonance (DSR) [1] is a particular solution of the complex cubic-quintic GinzburgLandau equation (CGLE) [2] . In passively mode-locked fiber laser, the DSR regime is manifesting with a square-pulse profile where the pulse energy increases without wave-breaking, with increasing pulse duration and constant peak power. The optical spectrum also remains invariant versus the pump power. In addition to these features, temporal coherence is a crucial characteristic of DSR, which results in the absence of fine structures within the square envelope. Many experimental results have been reported in different laser cavity configurations for square pulses with durations in the ps range but also in the ns to few hundreds of ns range. However, the coherence is investigated only in case of ultra-short pulses in the ps range [3] .