High-aspect-ratio dielectric pillar with nanocavity backed by metal substrate in the infrared range

Year: 2023

Authors: Lu XY., Tognazzi A., Cino AC., De Angelis C., Xu G., Zhang TY., Shishmarev D.

Autors Affiliation: Xinxiang Med Univ, Sch Med Engn, Xinxiang 453003, Peoples R China; Univ Palermo, Dept Engn, Viale Sci Ed 9, I-90128 Palermo, Italy; Consiglio Nazl Ric INO CNR, Ist Nazl Ott, Via Branze 38, I-25123 Brescia, Italy; Univ Brescia, Dept Informat Engn, Via Branze 38, I-25123 Brescia, Italy; Huazhong Univ Sci & Technol, Sch Opt & Elect Informat, Wuhan 430074, Peoples R China; Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; Univ Chinese Acad Sci, Beijing 100049, Peoples R China; Australian Natl Univ, John Curtin Sch Med Res, Canberra, ACT 2601, Australia.

Abstract: We investigated absorption and field enhancements of shallow nanocavities on top of high-aspect-ratio dielectric pillars in the infrared range. The structure includes a high-aspect-ratio nanopillar array of high refractive index, with nano-cavities on top of the pillars, and a metal plane at the bottom. The enhancement factor of electric field intensity reaches 3180 in the nanocavities and peak absorption reaches 99%. We also investigated the finite-size effect of the presented structure to simulate real experiments. Due to its narrow absorption bandwidth 3.5 nm, it can work as a refractive index sensor with sensitivity 297.5 nm/RIU and figure of merit 85. This paves the way to directly control light field at the nanoscales in the infrared light range. The investigated nanostructure will find applications in multifunctional photonics devices such as chips for culturing cells, refractive index sensors, biosensors of single molecule detection and nonlinear sensors.

Journal/Review: OPTICS EXPRESS

Volume: 31 (23)      Pages from: 39213  to: 39221

More Information: Horizon 2020 Framework Programme (899673) ; Ministero dell’Universita e della Ricerca (2020EY2LJT_002) ; National Health and Medical Research Council (GNT1173015) ; National Natural Science Foundation of China (6217144 3, 62275097) ; China Scholarship Council (202008410575) .
KeyWords: Field Enhancement; Nanoantennas; Metasurface; Absorber; Light
DOI: 10.1364/OE.506208

Connecting to view paper tab on IsiWeb: Click here