Effect of Unit Cell Shape on Switchable Infrared Metamaterial VO ₂ Absorbers/Emitters

Abstract

Metamaterial absorber/emitter is an important aspect of infrared radiation manipulation. In this paper, we proposed four simple switchable infrared metamaterial absorbers/emitters with Ag/VO2 disks on the Ag plane employing triangle, square, hexagon, and circle unit cells. The spectral absorption peaks whose intensities are above 0.99 occur at ~4 μm after structure optimization when VO2 is in insulating state and disappear when VO2 becomes metallic state. The simulated electromagnetic field reveals that the spectral absorption peaks are attributed to the excitation of magnetic polariton within the insulating VO2 spacer layer, whose values exceed 1.59 orders of magnitude higher than the incident magnetic field. Longer resonant wavelength would be excited in square arrays because its configuration is a better carrier of charges at the same spans. For absorption stability, the absorbers/emitters with square and circular structures do not have any change with the polarization angles changing from 0° to 90°, due to the high rotational symmetric structure. And four absorbers/emitters reveal similar shifts and attenuations under different incident angles. We believed that the switchable absorber/emitter demonstrates promising applications in the sensing technology and adaptive infrared system.

Bionic structures for optimizing the design of stealth materials

“…In addition, VO 2 can be transformed from a semiconductor to a metal state by heating it, to realize multi-spectral operation and achieve active infrared information camouflage. Li et al 78 further studied the influence of the unit shape arrangement on VO 2 infrared metamaterial, and adopted an Ag/VO 2 disk with triangular, square, hexagonal and circular unit arrangements on the Ag plane. When VO 2 is in the insulating state, the absorption peak of absorber/transmitter appears around 4 mm, which is greater than 0.99.…”

“…77 (c) Schematic of four switchable infrared metamaterial emitters consisting of Ag/VO 2 /Ag. 78 (d) The process of the preparation of multilayer sandwich fabric-based composite material. 82 (e) Schematic illustration of the fabrication route for Cr 2 O 3 @Ag hybrid pigment.…”

Ultra‐High Transmission Broadband Tunable VO2 Optical Limiter

“…This purpose is met effectively by smart materials such as vanadium dioxide (VO 2 ) because of the large contrast in optical constants across insulatorto-metal transition (IMT). [5,[15][16][17][18] Recent experiments show that the VO 2 is transparent in the insulating state and is well suited for IR imaging [19,20] ; the IMT of VO 2 occurs within 80 fs and attains stability over millions of switching cycles triggered by lasers, thus making it suitable for blocking high-intensity lasers. [21][22][23] Therefore, VO 2 OLs have attracted considerable interest for their overwhelming performance.…”