Core-shell particles as efficient broadband absorbers in infrared optical range

authored by: Andrey B. Evlyukhin, Khachatur V. Nerkararyan, Sergey I. Bozhevolnyi
Abstract: We demonstrate that efficient broadband absorption of infrared radiation can be obtained with deeply subwavelength spherical dielectric particles covered by a thin metal layer. Considerations based on Mie theory and the quasi-static approximation reveal a wide range of configuration parameters, within which the absorption cross section reaches the geometrical one and exceeds more than by order of magnitude the scattering cross section in the infrared spectrum. We show that the absorption is not only efficient but also broadband with the spectral width being close to the resonant wavelength corresponding to the maximum of the absorption cross section. We obtain a simple analytical expression for the absorption resonance that allows one to quickly identify the configuration parameters ensuring strong infrared absorption in a given spectral range. Relation between the absorption resonance and excitation of the short-range surface palsmon modes in the metal shell of particles is demonstrated and discussed. Our results can be used as practical guidelines for realization of efficient broadband infrared absorbers of subwavelength sizes desirable in diverse applications.
Organisation(s): Institute of Quantum Optics
PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
External Organisation(s): Yerevan State University
University of Southern Denmark
Type: Article
Journal: Optics express
Volume: 27
Pages: 17474-17481
No. of pages: 8
ISSN: 1094-4087
Publication date: 24.06.2019
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Atomic and Molecular Physics, and Optics
Electronic version(s): https://doi.org/10.1364/OE.27.017474 (Access: Open)
https://doi.org/10.15488/10437 (Access: Open)