title: Zero-lag synchronization and bubbling in delay-coupled lasers.
abstract: We show experimentally that two semiconductor lasers mutually coupled via a passive relay fiber loop exhibit chaos synchronization at zero lag, and study how this synchronized regime is lost as the lasers' pump currents are increased. We characterize the synchronization properties of the system with high temporal resolution in two different chaotic regimes, namely, low-frequency fluctuations and coherence collapse, identifying significant differences between them. In particular, a marked decrease in synchronization quality develops as the lasers enter the coherence collapse regime. Our high-resolution measurements allow us to establish that synchronization loss is associated with bubbling events, the frequency of which increases with increasing pump current.
authors.affiliation: Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Campus de Terrassa, Edif GAIA, Rambla de Sant Nebridi, Terrassa, E-08222 Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Tiana-Alsina
authors.forename: K
authors.initials: K
authors.lastname: Hicke
authors.forename: X
authors.initials: X
authors.lastname: Porte
authors.forename: M C
authors.initials: MC
authors.lastname: Soriano
authors.forename: M C
authors.initials: MC
authors.lastname: Torrent
authors.forename: J
authors.initials: J
authors.lastname: Garcia-Ojalvo
authors.forename: I
authors.initials: I
authors.lastname: Fischer