Sensors (Jun 2024)

High-Performance Refractive Index and Temperature Sensing Based on Toroidal Dipole in All-Dielectric Metasurface

  • Jingjing Zhao,
  • Xinye Fan,
  • Wenjing Fang,
  • Wenxing Xiao,
  • Fangxin Sun,
  • Chuanchuan Li,
  • Xin Wei,
  • Jifang Tao,
  • Yanling Wang,
  • Santosh Kumar

DOI
https://doi.org/10.3390/s24123943
Journal volume & issue
Vol. 24, no. 12
p. 3943

Abstract

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This article shows an all-dielectric metasurface consisting of “H”-shaped silicon disks with tilted splitting gaps, which can detect the temperature and refractive index (RI). By introducing asymmetry parameters that excite the quasi-BIC, there are three distinct Fano resonances with nearly 100% modulation depth, and the maximal quality factor (Q-factor) is over 104. The predominant roles of different electromagnetic excitations in three distinct modes are demonstrated through near-field analysis and multipole decomposition. A numerical analysis of resonance response based on different refractive indices reveals a RI sensitivity of 262 nm/RIU and figure of merit (FOM) of 2183 RIU−1. This sensor can detect temperature fluctuations with a temperature sensitivity of 59.5 pm/k. The proposed metasurface provides a novel method to induce powerful TD resonances and offers possibilities for the design of high-performance sensors.

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