Experimental study of single-shot polarization dynamics of dual dissipative solitons

Abstract

The state of polarization provides an additional dimension to the pulse dynamics of dissipative solitons. However, due to lack of appropriate measuring instruments, the polarization evolution of dual pulse vector solitons is still unclear. Here, for an erbium-doped fiber laser mode-locked with carbon nanotubes, we characterize the single-shot polarization evolution of dual dissipative solitons in detail using a high-speed wave-resolved measurement technique. For the different birefringence distributions in the laser cavity, the coupling between the orthogonal components of the vector soliton has a great influence on its physical properties, which may lead to various physical images of the vector soliton. We observed typical polarization-locked vector solitons and polarization attractors in the dual soliton pulses. We also observed that the polarization dynamics of the lead and tail vector pulses have similar evolution dynamics on the Poincaré sphere, while they have a distinct phase difference. By virtue of the difference of the processing SOPs between the leading and trailing pulses, we resolve three kinds of two solitons pulses with distinct relative phase evolutions. Our results enrich the vector soliton dynamics in fiber lasers.