A Mid-Infrared Narrowband Absorber Based on a Subwavelength Fine-Structured Silicon–Gold Metagrating

Applied Sciences

Jinliang Jie¹  Sen Zhang²  Yunxin Han²  Xin He²  Junbo Yang² 

[1] College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, China;Department of Physics, National University of Defense Technology, Changsha 410073, China;

关键词: perfect absorber;    narrowband;    grating;    mid-infrared;   

DOI  :  10.3390/app9235022

来源: DOAJ

【 摘 要 】

A subwavelength fine-structured silicon−gold metagrating was designed for realizing mid-infrared (mid-IR) narrowband absorbers. The metagrating consisted of a silicon grating on the stack of a gold film and a quartz substrate. The silicon grating consisted of two periodically arranged silicon strips in each unit cell. The numerical results reveal that perfect absorption of the traverse-magnetic (TM) polarized light at a wavelength of 4.071 μm can be achieved, with an absorption rate of ~99.2% and an absorption full-width at half-maximum (FWHM) bandwidth of ~31 nm. Thus, the proposed structure is useful for the spectral control of mid-IR signals. When used as a refractive index sensor, the structure has a measuring range of 1.0−2.0 with a quasi linear response, with a figure of merit (FOM) of ~103.

【 授权许可】

Unknown