Extremely Thin Perfect Absorber by Generalized Multipole Bianisotropic Effect

authored by: Hao Ma, Andrey B. Evlyukhin, Andrey E. Miroshnichenko, Fengjie Zhu, Siyu Duan, Jingbo Wu, Caihong Zhang, Jian Chen, Biaobing Jin, Willie J. Padilla, Kebin Fan
Abstract: Symmetry breaking plays a crucial role in understanding the fundamental physics underlying numerous physical phenomena, including the electromagnetic response in resonators, giving rise to intriguing effects such as directional light scattering, supercavity lasing, and topologically protected states. This work demonstrates that adding a small fraction of lossy metal (as low as 1 × 10⁻⁶ in volume) to a lossless dielectric resonator breaks inversion symmetry (IS), thereby lifting its degeneracy, leading to a strong bianisotropic response. In the case of the metasurface composed of such resonators, this effect leads to unidirectional perfect absorption while maintaining nearly perfect reflection from the opposite direction. It has developed more general Onsager-Casimir relations for the polarizabilities of particle arrays, taking into account the contributions of quadrupoles, which shows that bianisotropy is not solely due to dipoles, but also involves high-order multipoles. The experimental validation demonstrates an extremely thin terahertz-perfect absorber with a wavelength-to-thickness ratio of up to 25,000, where the material thickness is only 2% of the theoretical minimum thickness dictated by the fundamental limit. The findings can pave a new route to design devices for applications involving optical-to-heat conversion processes.
Organisation(s): Institute of Quantum Optics
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
External Organisation(s): Nanjing University
Purple Mountain Laboratories
University of New South Wales (UNSW)
Duke University
Type: Article
Journal: Advanced optical materials
Volume: 12
ISSN: 2195-1071
Publication date: 13.03.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Atomic and Molecular Physics, and Optics
Electronic version(s): https://doi.org/10.48550/arXiv.2308.07139 (Access: Open)
https://doi.org/10.1002/adom.202301968 (Access: Closed)