Terahertz investigation of bound states in the continuum of metallic metasurfaces
Abstract
The concept of “bound states in the continuum” (BIC) describes an idealized physical system exhibiting zero radiative loss composed, for example, of an infinitely extended array of resonators. In principle, vanishing of radiative losses enables an infinitely high-quality factor and corresponding infinite lifetime of the resonance. As such, BIC inspired metasurfaces and photonic designs aim to achieve superior performance in various applications including sensing and lasing. We describe an analytical model based on temporal coupled mode theory to realize an “accidental” (i.e., parameter-tuned) Friedrich–Wintgen BIC. Further, we experimentally verify this model with measurements of quasi-BICs in a metallic terahertz metasurface (MS) and the corresponding complementary metasurface (CMS) using terahertz time domain spectroscopy. For the MS and CMS structures, quality factors of ∼ 20 are achieved, limited by non-radiative intrinsic loss in the materials. Our results reveal that Babinet’s principle qualitatively holds for the MS and CMS quasi-BIC structures. In addition, ultra-high electric and magnetic field enhancement MS and CMS structures, respectively, are presented.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 03, 2020
- Source ID
- 10.1364/optica.404754
Entities
People
- Chunxu Chen
- Ian Hammock
- Kelson Kaj
- Richard D. Averitt
- Xiaoguang Zhao
- Xin Zhang
- Yuwei Huang
Organizations
- Defense Advanced Research Projects Agency
- National Science Foundation