title: Dynamical characterization of chaotic itinerancy in a three-mode laser subjected to frequency-shifted optical feedback.
abstract: We investigated chaotic dynamics in a microchip three-mode solid-state laser subjected to frequency-shifted optical feedback. When the frequency shift was tuned to harmonic frequencies of the relaxation oscillation, a bifurcation from a periodic sustained relaxation oscillation ("soft-mode") state to a chaotic spiking ("hard-mode") state via a chaotic itinerancy was observed as the feedback intensity was increased. Dynamic characterizations of modal interplay and self-induced switching between the soft- and hard-mode chaotic states over times (i.e., chaotic itinerancy) were carried out by the information circulation analysis and joint time-frequency analysis of long-term experimental time series. Drastic changes in information transfer rates among oscillating modes and occasional frequency locking among periodicities of two chaotic states associated with switchings were identified in chaotic itinerancy. Essential dynamical behaviors were reproduced by numerical simulation.
authors.affiliation: Department of Human and Information Science, Tokai University, 1117 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Miyasaka
authors.forename: Kenju
authors.initials: K
authors.lastname: Otsuka
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Maniwa
authors.forename: Jing-Yuan
authors.initials: JY
authors.lastname: Ko