Real-time observation of stationary and pulsating noise-like vector pulses in a fiber laser

Abstract

Rapid progress in real-time measurement technology has uncovered varieties of transient pulse dynamics. Here, we report the vector nature of noise-like pulse (NLP) in a passive fiber laser based on the nonlinear optical loop mirror (NOLM) as the polarization independent saturable absorber. After achieving the basic operation regime of NLP, various types of vector pulses, namely, the polarization locked noise-like vector pulse (PLNLVP), the group velocity locked noise-like vector pulse (GVLNLVP), and the transitional state of combined characteristics of GVLNLVP and polarization rotation noise-like vector pulse (PRNLVP) are also obtained in the cavity. Besides, by utilizing the Dispersive Fourier transform (DFT) technique, the spectral evolution and the energy vibration of pulsating PLNLVP, GVLNLVP, and the transitional state of combined characteristics of GVLNLVP and PRNLVP are also analyzed in real time. Particularly, the coexisting pulsation vector state of NLP and soliton is also captured. All these findings will help to complement our understanding of noise-like vector pulses (NLVPs) in a fiber laser.

Pulsating dynamics of noise-like pulses in a fiber laser with nonlinear optical loop mirror

“…After that, real-time spectral characterization by DFT method becomes an efficient way to investigate the transient dynamics of NLP. These researches were mainly focused on vector features [34], pulsating dynamics [35], generation of rogue wave as well as complex instability dynamics [36]. Particularly, far more complex NLP dynamics have been reported under the condition of the 'Q-switched-like' instability [37][38][39][40].…”