Bright and dark vector rogue waves

Abstract

For an Erbium-doped mode locked fibre laser, we demonstrate experimentally a new type of vector rogue waves (RWs) emergence of which is caused by the coherent coupling of the orthogonal states of polarisation (SOPs). Unlike weak interaction between neighbouring dissipative solitons for the soliton rain, this creates a new type of the energy landscape where the interaction of the orthogonal SOPs leads to polarisation trapping or escapes from the trapping triggered by polarisation instabilities and so results in the pulse dynamics satisfying criteria of the "dark" and "bright" RWs. The obtained results, apart from the fundamental interest, can provide a base for development of the rogue waves mitigation techniques in the context of the applications in photonics and beyond. Keywords: mode locked lasers, rogue waves, polarisation INTRODUCTIONThe femtosecond/picosecond pulsewidth and MHz repetition rate of mode locked fibre lasers (MLFLs) provide an opportunity to observe more data on rogue waves in the form of the chaotic bunches of pulses (soliton rain We support the concept in this paper by providing an experimental evidence of a new type of the energy landscape created by the interaction of the orthogonal states of polarisation (SOPs) and leading to the polarisation trapping or escape from the trapping which is triggered by polarisation instabilities [12]- [13]. We demonstrate that tuning the in-cavity and the pump polarisation controllers, i.e. cavity birefringence and the ellipticity of the pump wave, enable transitions between two orthogonal states of polarisation which leads to output power distribution satisfying the rogue wave's criteria.