High Q-factor, high contrast, and multi-band optical sensor based on plasmonic square bracket dimer metasurface

Ni, B., Chu, G., Xu, Z., Hou, L. , Liu, X. and Xiong, J. (2024) High Q-factor, high contrast, and multi-band optical sensor based on plasmonic square bracket dimer metasurface. Nanomaterials, 14(5), 421. (doi: 10.3390/nano14050421)

Abstract

A high-performance resonant metasurface is rather promising for diverse application areas such as optical sensing and filtering. Herein, a metal–insulator–metal (MIM) optical sensor with merits of a high quality-factor (Q-factor), multiple operating bands, and high spectrum contrast is proposed using plasmonic square bracket dimer metasurface. Due to the complex square bracket itself, a dimer structure of two oppositely placed square brackets, and metasurface array configuration, multiple kinds of mode coupling can be devised in the inner and outer elements within the metasurface, enabling four sensing channels with the sensitivities higher than 200 nm/RIU for refractive index sensing. Among them, the special sensing channel based on the reflection-type surface lattice resonance (SLR) mechanism has a full width at half maximum (FWHM) of only 2 nm, a high peak-to-dip signal contrast of 0.82, a high Q-factor of 548, and it can also behave as a good sensing channel for the thickness measurement of the deposition layer. The multi-band sensor can work normally in a large refractive index or thickness range, and the number of resonant channels can be further increased by simply breaking the structural symmetry or changing the polarization angle of incident light. Equipped with unique advantages, the suggested plasmonic metasurface has great potential in sensing, monitoring, filtering, and other applications.

• Item Type: Articles
• Additional Information: Funding: This work was supported by the National Natural Science Foundation of China (No. 62105155), the Natural Science Foundation of Jiangsu Province (BK20210326), and the Ministry of Education collaborative project (B17023).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Liu, Professor Xuefeng and Hou, Dr Lianping

Creator Roles

Hou, L.: Writing – review and editing
Liu, X.: Formal analysis, Supervision, Project administration

• Authors: Ni, B., Chu, G., Xu, Z., Hou, L., Liu, X., and Xiong, J.
• College/School: College of Science and Engineering > School of Engineering; College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Nanomaterials
• Publisher: MDPI
• ISSN: 2079-4991
• ISSN (Online): 2079-4991
• Copyright Holders: Copyright: © 2024 by the authors
• First Published: First published in Nanomaterials 14(5): 421
• Publisher Policy: Reproduced under a Creative Commons licence