用于传感应用的具有超稀疏纳米线网格的超窄带介质超材料吸收器。

Liao Yan-Lin, Zhao Yan

Key Lab of Opto-electronic Information Acquisition and Manipulation, Ministry of Education, Anhui University, Hefei, 230039, China.

State Key Laboratory of Pulsed Power Laser Technology, Hefei, 230037, China.

Sci Rep. 2020 Jan 30;10(1):1480. doi: 10.1038/s41598-020-58456-y.

Due to their low losses, dielectric metamaterials provide an ideal resolution to construct ultra-narrowband absorbers. To improve the sensing performance, we present numerically a near-infrared ultra-narrowband absorber by putting ultra-sparse dielectric nanowire grids on metal substrate in this paper. The simulation results show that the absorber has an absorption rate larger than 0.99 with full width at half-maximum (FWHM) of 0.38 nm. The simulation field distribution also indicates that the ultra-narrowband absorption is originated from the low loss in the guided-mode resonance. Thanks to the ultra-narrow absorption bandwidths and the electric field mainly distributed out of the ultra-sparse dielectric nanowire grids, our absorber has a high sensitivity S of 1052 nm/RIU and a large figure of merit (FOM) of 2768 which mean that this ultra-narrowband absorber can be applied as a high-performance refractive index sensor.

由于其低损耗特性，介电超材料为构建超窄带吸收器提供了理想的解决方案。为了提高传感性能，本文通过在金属衬底上放置超稀疏介电纳米线网格，数值模拟展示了一种近红外超窄带吸收器。模拟结果表明，该吸收器的吸收率大于0.99，半高宽（FWHM）为0.38 nm。模拟场分布还表明，超窄带吸收源于导模共振中的低损耗。得益于超窄的吸收带宽以及电场主要分布在超稀疏介电纳米线网格之外，我们的吸收器具有1052 nm/RIU的高灵敏度S和2768的大品质因数（FOM），这意味着这种超窄带吸收器可作为高性能折射率传感器应用。