Soliton patterns recognition and searching from a 2 µm intelligent mode-locked fiber laser agent

Abstract

The negative dispersion of silica fibers near 2 µm wavelength leads to formations of attractive soliton-patterns in Thulium-doped mode-locked fiber lasers (TDMLFL), including single-solitons(SS), bound-solitons(BS), multi-solitons(MS), soliton molecules(SM), as well as noise-like pulses(NLP). However, the current manual or physically controlled methods cannot accurately identify and quickly adjust the diverse solitons. Here, we successfully realized the fine identification and automatic searching of continuous waves, Q-switching, noise-like pulses, multi-solitons, and single-solitons by constructing a genetic algorithm based self-tuning pump power and time-spectrum feedback agent in a TDMLFL. The searched SS have a duration of 1.269 ps, a central wavelength of 1966 nm and a typical Kelly-sideband spectrum. The minimum consuming time of globally finding a single-soliton is ∼40 mins, and the corresponding recovery-time is ∼2 mins. To the best of our knowledge, this is the first time that an intelligent searching and recognition of single soliton in 2 µm TDMLFL and also the first report of soliton-patterns fully intelligent identification and searching without prior parameters in soliton mode locked fiber lasers.