title: Chaos synchronization and spontaneous symmetry-breaking in symmetrically delay-coupled semiconductor lasers.
abstract: We present experimental and numerical investigations of the dynamics of two device-identical, optically coupled semiconductor lasers exhibiting a delay in the coupling. Our results give evidence for subnanosecond coupling-induced synchronized chaotic dynamics in conjunction with a spontaneous symmetry-breaking: we find a well-defined time lag between the dynamics of the two lasers, and an asymmetric physical role of the subsystems. We demonstrate that the leading laser synchronizes its lagging counterpart, whereas the synchronized lagging laser drives the coupling-induced instabilities.
authors.affiliation: Institute of Applied Physics, Darmstadt University of Technology, Schlossgartenstrasse 7, D-64289 Darmstadt, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Heil
authors.forename: I
authors.initials: I
authors.lastname: Fischer
authors.forename: W
authors.initials: W
authors.lastname: Elsässer
authors.forename: J
authors.initials: J
authors.lastname: Mulet
authors.forename: C R
authors.initials: CR
authors.lastname: Mirasso