Topologically protected broadband rerouting of propagating waves around complex objects

Nanophotonics

article

Zeki Hayran¹  Seyyed Ali Hassani Gangaraj¹  Francesco Monticone¹ 

[1] School of Electrical and Computer Engineering, Cornell University

关键词: photonic topological materials;    nonreciprocity;    magnetized plasmas;    surface plasmon-polaritons;    leaky waves;   

DOI  :  10.1515/nanoph-2019-0075

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Achieving robust propagation and guiding of electromagnetic waves through complex and disordered structures is a major goal of modern photonics research, for both classical and quantum applications. Although the realization of backscattering-free and disorder-immune guided waves has recently become possible through various photonic schemes inspired by topological insulators in condensed matter physics, the interaction between such topologically protected guided waves and free-space propagating waves remains mostly unexplored, especially in the context of scattering systems. Here, we theoretically demonstrate that free-space propagating plane waves can be efficiently coupled into topological one-way surface waves, which can seamlessly flow around sharp corners and electrically large barriers and release their energy back into free space in the form of leaky-wave radiation. We exploit this physical mechanism to realize topologically protected wave-rerouting around an electrically large impenetrable object of complex shape, with transmission efficiency exceeding 90%, over a relatively broad bandwidth. The proposed topological wave-rerouting scheme is based on a stratified structure composed of a topologically nontrivial magnetized plasmonic material coated by a suitable isotropic layer. Our results may open a new avenue in the field of topological photonics and electromagnetics, for applications that require engineered interactions between guided waves and free-space propagating waves, including for complex beam-routing systems and advanced stealth technology. More generally, our work may pave the way for robust defect/damage-immune scattering and radiating systems.

【 授权许可】

CC BY