title: Observation of optical solitons in PT-symmetric lattices.
abstract: Controlling light transport in nonlinear active environments is a topic of considerable interest in the field of optics. In such complex arrangements, of particular importance is to devise strategies to subdue chaotic behaviour even in the presence of gain/loss and nonlinearity, which often assume adversarial roles. Quite recently, notions of parity-time (PT) symmetry have been suggested in photonic settings as a means to enforce stable energy flow in platforms that simultaneously employ both amplification and attenuation. Here we report the experimental observation of optical solitons in PT-symmetric lattices. Unlike other non-conservative nonlinear arrangements where self-trapped states appear as fixed points in the parameter space of the governing equations, discrete PT solitons form a continuous parametric family of solutions. The possibility of synthesizing PT-symmetric saturable absorbers, where a nonlinear wave finds a lossless path through an otherwise absorptive system is also demonstrated.
authors.affiliation: 1] Institute of Optics, Information and Photonics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 7/B2, 91058 Erlangen, Germany [2] Erlangen Graduate School in Advanced Optical Technologies (SAOT), 91058 Erlangen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Wimmer
authors.affiliation: Institute of Optics, Information and Photonics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 7/B2, 91058 Erlangen, Germany.
authors.forename: Alois
authors.initials: A
authors.lastname: Regensburger
authors.affiliation: CREOL, College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816-2700, USA.
authors.forename: Mohammad-Ali
authors.initials: MA
authors.lastname: Miri
authors.affiliation: Institute of Optics, Information and Photonics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 7/B2, 91058 Erlangen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Bersch
authors.affiliation: CREOL, College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816-2700, USA.
authors.forename: Demetrios N
authors.initials: DN
authors.lastname: Christodoulides
authors.affiliation: Institute of Solid State Theory and Optics, Friedrich Schiller University Jena, Max-Wien-Platz 1, 07743 Jena.
authors.forename: Ulf
authors.initials: U
authors.lastname: Peschel