Abstract
The kagome lattice is a two-dimensional network of corner-sharing triangles and is often associated with geometrical frustration. In particular, the frustrated coupling between waveguide modes in a kagome array leads to a dispersionless flat band consisting of spatially localized modes. Here we propose a complex photonic lattice by placing -symmetric dimers at the kagome lattice points. Each dimer corresponds to a pair of strongly coupled waveguides. With balanced arrangement of gain and loss on individual dimers, the system exhibits a -symmetric phase for finite gain/loss parameter up to a critical value. The beam evolution in this complex kagome waveguide array exhibits a novel oscillatory rotation of optical power along the propagation distance. Long-lived local chiral structures originating from the nearly flat bands of the kagome structure are observed when the lattice is subject to a narrow beam excitation.
© 2015 Optical Society of America
Full Article | PDF ArticleMore Like This
Nicholas Bender, Hamidreza Ramezani, and Tsampikos Kottos
Opt. Lett. 40(9) 2138-2141 (2015)
P. A. Brandão, M. J. Cirino, and S. B. Cavalcanti
Opt. Lett. 49(3) 618-621 (2024)
Ying Chen, Xiancong Lu, and Huanyang Chen
Opt. Lett. 44(17) 4251-4254 (2019)