Unidirectional edge modes are achieved in gyromagnetic photonic crystals. The physical reason is attributed to magnetic resonance and broken time-reversal symmetry under external magnetic fields. These edge modes propagate only along a single direction, while the backward modes are completely suppressed. The unidirectional transmittance is nearly 100% and hardly affected by perfect electric conductor (PEC) defect. However, a PEC defect has sensitive influence on both the phase delay and pattern distribution of unidirectional edge modes. These properties hold promise in designing various unidirectional devices. Here we design a three port circulator with high transmission contrast and magnetic controllability simultaneously.

Date Published: 16 September 2016
PDF: 6 pages
Proc. SPIE 9918, Metamaterials, Metadevices, and Metasystems 2016, 99182H (16 September 2016); doi: 10.1117/12.2236158

Published in SPIE Proceedings Vol. 9918:
Metamaterials, Metadevices, and Metasystems 2016
Nader Engheta; Mikhail A. Noginov; Nikolay I. Zheludev, Editor(s)