Abstract
Most chiral metamaterials and meta surfaces are designed to operate in a single wavelength band and with a certain circular dichroism (CD) value. Here, mid-infrared chiral meta surface absorbers with selective CD in dual-wavelength bands are designed and demonstrated. The dual-band CD selectivity and tunability in the chiral meta surface absorbers are enabled by the unique design of a unit cell with two coupled rectangular bars. It is shown that the sign of CD in each wavelength band can be independently controlled and flipped by simply adjusting the geometric parameters, the width and the length, of the vertical rectangular bars. The mechanism of the dual-band CD selection in the chiral meta surface absorber is further revealed by studying the electric field and magnetic field distributions of the antibonding and bonding modes supported in the coupled bars under circularly polarized incident light. Furthermore, the chiral resonance wavelength can be continuously increased by scaling up the geometric parameters of the meta surface unit cell. The demonstrated results will contribute to the advance of future mid-infrared applications such as chiral molecular sensing, thermophotovoltaics, and optical communication.
Recommended Citation
H. Tang et al., "Dual-Band Selective Circular Dichroism in Mid-Infrared Chiral Metasurfaces," Optics Express, vol. 30, no. 11, pp. 20063 - 20075, Optica, May 2022.
The definitive version is available at https://doi.org/10.1364/OE.457218
Department(s)
Mechanical and Aerospace Engineering
International Standard Serial Number (ISSN)
1094-4087
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2023 Optica, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
23 May 2022
PubMed ID
36221765
Comments
U.S. Department of Energy, Grant DE-AC02-06CH11357