Work

Polarization-Insensitive Dual-Band Response Governed by Quasi Bound States in the Continuum for High-Performance Refractive Index Sensing

Year: 2021

Type: article

Abstract: The introduction of distortions into the metasurfaces with in-plane symmetry offers a possibility to achieve resonances with high quality (Q) factors, but such distortions make the metasurfaces sensitive to the polarization state of the incident light. Here, we propose and numerically demonstrate a polarization-insensitive dual-band refractive index (RI) sensor. In this work, the proposed metasurface is imparted with fourfold symmetry by combining two pairs of asymmetric silicon elliptical nanodisks, allowing it to acquire polarization-insensitive properties to the incident light. Two narrow-band reflection peaks with full width at half maximum (FWHM) of 3.36 nm and 4.53 nm are excited and tailored for RI sensing. Their sensitivities are 2756.67 nm/RIU and 2319.93 nm/RIU, with figure of merit (FOM) values of 820.44 RIU−1 and 532.09 RIU−1. This work provides a new approach to realize polarization-independent and high-performance RI sensor devices.

Source: Results in Physics

DOI: 10.1016/j.rinp.2021.105125

Authors: Wenjun Liu, Zhongzhu Liang, Zheng Qin, Xiaoyan Shi, Fuming Yang, Dejia Meng