Phase Interrogation Sensor Based on All-Dielectric BIC Metasurface

Abstract

The low performance of sensors based on an all-dielectric metasurface limits their application compared to metallic counterparts. Here, for the first time, an all-dielectric BIC (bound states in the continuum) metasurface is employed for highly sensitive phase interrogation refractive index sensing. The proposed sensor is well analyzed, fabricated, and characterized. Experimentally, a high-performance BIC-based microfluidic sensing chip with a Q factor of 1200 is achieved by introducing symmetry breaking. A refractive index sensor with high figure of merit of 418 RIU–1 is demonstrated, which is beneficial to the phase interrogation. Notably, we measure a record phase interrogation sensitivity of 2.7 × 104 deg/RIU to the refractive index, thus enabling the all-dielectric BIC to rival the refractive index detection capabilities of metal-based sensors such as surface plasmon resonance. This scheme establishes a pivotal role of the all-dielectric metasurface in the field of ultrahigh sensitivity sensors and opens possibilities for trace detection in biochemical analysis and environment monitoring.

Ultra-Sensitive Refractive Index Sensing Based on Quasi-BICs in All-Dielectric Nanorod Array

“…It is compatible with semiconductor micronanofabrication processes (lithography, etching, etc.) [48,49].…”

“…It is compatible with semiconductor micronanofabrication processes (lithography, etching, etc.) [48,49]. First, photoresist is spin-coated on a sufficiently cleaned quartz substrate, and after the photoresist is sufficiently cured, the PMMA nanoarray structure is obtained by electron beam lithography.…”

Emerging metasurfaces for refractometric sensing: fundamental and applications

“…In addition, it is also found that increasing height of the nanorods leads to an enhanced sensing performance, which is due to the enlarged contacting surface area between the nanostructures to the environmental media. Liu et al propose and fabricate a similar metasurface array consisting of periodic silicon nanorod pairs placed on a silica substrate (figures 11(f) and (g)) [106]. With combined microfluidic chips, NaCl solutions with different mass fractions (0.00%, 0.10%, 0.30%, 0.50%, 0.70%, 1.00%, and 3.00%) are prepared to evaluate the sensing performance with RIs change from 1.318 to 1.358 (figure 11(h)).…”

Optical Sensing Using Hybrid Multilayer Grating Metasurfaces with Customized Spectral Response

“…Different designs have been applied to enhance the coupling of the incoming light to the SPR [4,5]. The mechanisms of such devices are purely optical-, phase-, spectral-, angular-, or intensity-interrogated [6][7][8][9][10][11]. A modern simplification of these sensors is obtained by attaching them to photodetectors, which extract the measurable quantity from an electrical signal [12,13].…”