Coherence loss of partially mode-locked fibre laser
Autori: Gao L., Zhu T., Wabnitz S., Liu M., Huang W.
Affiliazione autori: Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Chongqing University, Chongqing, 400044, China; Dipartimento di Ingegneria dell Informazione, Università degli Studi di Brescia, INO-CNR, via Branze 38, Brescia, 25123, Italy
Abstract: Stochastically driven nonlinear processes limit the number of amplified modes in a natural system due to competitive mode interaction, which is accompanied by loss of coherence when increasing the complexity of the system. Specifically, we find that modulation instability, which exhibits great fluctuations when it spontaneously grows from noise in conservative systems, may possess a high degree of coherence in dissipative laser system with gain. Nonlinear mode interactions can be competitive or cooperative: adjusting the intracavity polarization state controls the process of loss of coherence. Single-shot spectra reveal that, first, the fibre laser redistributes its energy from the center wavelength mode into sidebands through parametric instabilities. Subsequently, longitudinal modes are populated via cascaded four-wave-mixing. Parametric frequency conversion populates longitudinal modes with a random distribution of position, intensity and polarization, resulting in partially (rather than highly) coherent pulses. These dynamics unveil a new route towards complex pattern formation in nonlinear laser systems, and they may be also beneficial for the understanding of supercontinuum, Kerr-combs phenomena, and optical rogue waves.
Giornale/Rivista: SCIENTIFIC REPORTS
Volume: 6 Da Pagina: 24995-1 A: 24995-12
Parole chiavi: NOISE-LIKE PULSES; MODULATION INSTABILITY; ULTRAFAST LASER; FREQUENCY COMBS; RING CAVITY; GENERATION; GRAPHENE; FLUCTUATIONS; CHIPDOI: 10.1038/srep24995Citazioni: 21dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2023-12-10Riferimenti tratti da Isi Web of Knowledge: (solo abbonati) Link per visualizzare la scheda su IsiWeb: Clicca quiLink per visualizzare la citazioni su IsiWeb: Clicca qui