Recently, a research team led by Dr. Guo Haitao from the Photonic Functional Materials and Devices Laboratory at the Xi'an Institute of Optics and Mechanics of the Chinese Academy of Sciences has made significant progress in the study of mid-infrared fiber laser pulsating soliton dynamics. The research findings, titled "Double-periodic pulsating solitons in 2.8 μm mid-infrared fiber laser," have been published in the journal Chaos, Solitons and Fractals.
Mid-infrared ultrafast fiber lasers, with their high conversion efficiency, compact structure, excellent mode quality, and broad emission spectrum, hold great promise for applications in spectroscopy, medical surgery, and materials processing. However, optimizing their performance remains challenging due to issues such as nonlinear effects, dispersion control, and complex pulse dynamics. Under high pump intensity, the double-period pulsed solitons induced by nonlinear effects exhibit a composite characteristic of long and short periods, serving as a typical example of nonlinear dynamics research. This phenomenon holds significant implications for the application of laser technology in fields such as information encoding, optical storage, and optical communication.
The research team systematically investigated the dynamical characteristics of double-period pulsed solitons in mid-infrared ultrafast fiber lasers based on the complex Ginzburg-Landau equation. By controlling the pump power of a 2.8 μm erbium-doped fluoride mode-locked fiber laser, the team achieved a transition from steady-state single pulses to pulsed solitons, bound solitons, and finally to three-soliton molecules and four-soliton molecules. The team observed multiple sets of short periods (13, 9, 4, 11, 7, 10, 3) and long periods (425, 86, 105, 216, 648, 823, 90) coexisting in double-period pulsed solitons, whose dynamics exhibited a mixed mode of short-period and long-period pulsations. The study found that as the pumping power increases, the short period of the pulsed soliton remains constant, while the long period gradually increases.
This study has for the first time revealed the dynamical mechanism of double-period pulsed solitons in mid-infrared fiber lasers, not only deepening our understanding of pulse nonlinear behavior in anomalous dispersion laser systems but also providing new insights for optimizing mid-infrared ultrafast laser pulses, which may find applications in molecular spectroscopy and precision material processing.
The research was supported by the National Natural Science Foundation of China Major Project and the Chinese Academy of Sciences Youth Innovation Promotion Association Project.
