Open AccessLow-amplitude, drifting sub-pulses hiding in background of noise-like pulse generated in fiber laser
Author(s) -
Jiachen Wang,
Jun He,
Changrui Liao,
Yiping Wang
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.029606
Subject(s) - oscilloscope , optics , physics , amplitude , noise (video) , waveform , pulse (music) , laser , bandwidth limited pulse , pulse amplitude modulation , autocorrelation , optical fiber , ultrashort pulse , computer science , detector , statistics , mathematics , quantum mechanics , voltage , artificial intelligence , image (mathematics)
We report a puzzling dynamic observed in a passively mode-locked fiber laser operating in the noise-like pulse regime, in which low-amplitude sub-structures emerge and drift away from the main waveform of the NLP pulse packet. The peak amplitudes of the drifting sub-pulses are orders of magnitude lower than the main packet when the NLP is monitored with a low-speed detecting system, a fact that makes the sub-pulses entirely hide in the background of the pulse train as the oscilloscope trace is displayed in a coarse amplitude resolution. Moreover, the presence of the low-amplitude sub-pulses cannot be detected in ordinary characteristics like optical spectrum, radio-frequency spectrum, and autocorrelation trace. We speculate that such a dynamic may extensively exist in fiber lasers operating in the noise-like pulse regime, and is just overlooked in the previous research efforts due to the difficulty to observe it. The discovery of this intriguing dynamic is informative for investigating the mechanisms of noise-like pulse.