Transient dynamics of pulsating polarization rotating dual solitons in an ultrafast fiber laser.

The state of polarization is essential for a full description of ultrashort pulses. We experimentally observe the transient vector dynamics of pulsating vector solitons with rotating polarizations in a single-wall carbon nanotube mode-locked fiber laser. We acquire the single-shot polarization evolution of two different dual soliton pulsations using a homemade real-time wavelength-resolved state of polarization measurement system. We identify experimentally two different types of dual-soliton pulsations with longer and shorter pulsating periods respectively, and we find that dispersive-caused wave-caused energy exchange may be the reason for the distinct single soliton polarization evolution in multi-soliton cases. Our results are crucial for understanding the essence of soliton behaviour and developing novel potential applications of ultrafast fiber lasers.