Observation of optical solitons in PT-symmetric lattices

• Published in: Nature communications 2015-07, Vol.6 (1), p.7782-7782, Article 7782
• Main Authors: Wimmer, Martin, Regensburger, Alois, Miri, Mohammad-Ali, Bersch, Christoph, Christodoulides, Demetrios N., Peschel, Ulf
• Format: Article
• Language: English
• Subjects: 639/766/400/385; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms8782

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. Parity–time symmetry can impose a stable energy flow in photonic systems with simultaneous amplification and attenuation. Here, Wimmer et al. demonstrate optical solitons belonging to a continuous parametric family of solutions in a parity–time-symmetric lattice and observe saturable absorber action.