Localized single frequency lasing states in a finite parity-time symmetric resonator chain

Phang, Sendy; Vukovic, Ana; Creagh, Stephen C.; Sewell, Phillip; Gradoni, Gabriele; Benson, Trevor M.

Abstract

In this paper a practical case of a finite periodic Parity Time chain made of resonant dielectric cylinders is considered. The paper analyzes a more general case where PT symmetry is achieved by modulating both the real and imaginary part of the material refractive index along the resonator chain. The band-structure of the finite periodic PT resonator chains is compared to infinite chains in order to understand the complex interdependence of the Bloch phase and the amount of the gain/loss in the system that causes the PT symmetry to break. The results show that the type of the modulation along the unit cell can significantly affect the position of the threshold point of the PT system. In all cases the lowest threshold is achieved near the end of the Brillouin zone. In the case of finite PT-chains, and for a particular type of modulation, early PT symmetry breaking is observed and shown to be caused by the presence of termination states localized at the edges of the finite chain resulting in localized lasing and dissipative modes at each end of the chain.

Citation

Phang, S., Vukovic, A., Creagh, S. C., Sewell, P., Gradoni, G., & Benson, T. M. (2016). Localized single frequency lasing states in a finite parity-time symmetric resonator chain. Scientific Reports, 6, Article e20499. https://doi.org/10.1038/srep20499

• Journal Article Type: Article
• Publication Date: Feb 5, 2016
• Deposit Date: Feb 10, 2016
• Publicly Available Date: Feb 10, 2016
• Journal: Scientific Reports
• Electronic ISSN: 2045-2322
• Publisher: Nature Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Article Number: e20499
• DOI: https://doi.org/10.1038/srep20499
• Keywords: Metamaterials, Microresonators, Optoelectronic devices and components
• Public URL: https://nottingham-repository.worktribe.com/output/776979
• Publisher URL: http://www.nature.com/articles/srep20499