We theoretically study the properties of unidirectional edge modes in a magnetic metamaterial waveguide and their applications in tunable multi-way splitters. These edge modes can only be excited at the surface to propagate along a single direction with nearly perfect transmittance of 100%. The physical origin is attributed to the combined action of magnetic resonance and time-reversal symmetry breaking under external magnetic fields. Moreover, the propagation direction can be controlled by reversing the direction of the external magnetic field. Further study reveals that a perfect electric conductor defect scarcely affects the transmittance but has sensitive influence on the phase delay and pattern distribution of the unidirectional edge modes. These properties hold promise for designing various unidirectional photonic devices. As an example, we design a tunable multi-way splitter with the advantages of high transmission contrast and convenient pathway control simultaneously.

Date Published: 15 October 2015
PDF: 7 pages
Proc. SPIE 9676, AOPC 2015: Optical Design and Manufacturing Technologies, 96760A (15 October 2015); doi: 10.1117/12.2197770

Published in SPIE Proceedings Vol. 9676:
AOPC 2015: Optical Design and Manufacturing Technologies
Lin Li; Kevin P. Thompson; Ligong Zheng, Editor(s)