Revelation of the birth and extinction dynamics of solitons in SWNT-mode-locked fiber lasers  

作　　者：YUDONG CUI XUEMING LIU 

机构地区：[1]State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University [2]Institute for Advanced Interdisciplinary Research, Nanjing University of Aeronautics and Astronautics [3]School of Physics and Electronic Science, Hunan University of Science and Technology

出　　处：《Photonics Research》2019年第4期423-430,共8页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(NSFC)(11774310,61525505,61705193);China Postdoctoral Science Foundation(2017M610367)

摘　　要：The dispersive Fourier transform(DFT) technique opens a fascinating pathway to explore ultrafast non-repetitive events and has been employed to study the build-up process of mode-locked lasers. However, the shutting process for the mode-locked fiber laser seems to be beyond the scope of researchers, and the starting dynamics under nearzero dispersion remains unclear. Here, the complete evolution dynamics(from birth to extinction) of the conventional soliton(CS), stretched pulse(SP), and dissipative soliton(DS) are investigated by using the DFT technique.CS, SP, and DS fiber lasers mode locked by single-walled carbon nanotubes(SWNTs) are implemented via engineering the intracavity dispersion map. The relaxation oscillation can always be observed before the formation of stable pulse operation due to the inherent advantage of SWNT, but it exhibits distinct evolution dynamics in the starting and shutting processes. The shutting processes are dependent on the dispersion condition and turn-off time, which is against common sense. Some critical phenomena are also observed, including transient complex spectrum broadening and frequency-shift interaction of SPs and picosecond pulses. These results will further deepen understanding of the mode-locked fiber laser from a real-time point of view and are helpful for laser design and applications.The dispersive Fourier transform(DFT) technique opens a fascinating pathway to explore ultrafast non-repetitive events and has been employed to study the build-up process of mode-locked lasers. However, the shutting process for the mode-locked fiber laser seems to be beyond the scope of researchers, and the starting dynamics under nearzero dispersion remains unclear. Here, the complete evolution dynamics(from birth to extinction) of the conventional soliton(CS), stretched pulse(SP), and dissipative soliton(DS) are investigated by using the DFT technique.CS, SP, and DS fiber lasers mode locked by single-walled carbon nanotubes(SWNTs) are implemented via engineering the intracavity dispersion map. The relaxation oscillation can always be observed before the formation of stable pulse operation due to the inherent advantage of SWNT, but it exhibits distinct evolution dynamics in the starting and shutting processes. The shutting processes are dependent on the dispersion condition and turn-off time, which is against common sense. Some critical phenomena are also observed, including transient complex spectrum broadening and frequency-shift interaction of SPs and picosecond pulses. These results will further deepen understanding of the mode-locked fiber laser from a real-time point of view and are helpful for laser design and applications.

关 键 词：dispersive Fourier transform(DFT) fascinating pathway PICOSECOND pulses 

分 类 号：O4[理学—物理]