Polarization-Independent Multi-Resonance With High Q-Factor for Highly Sensitive Terahertz Sensors Based on All-Dielectric Metasurface

Abstract

Since the fingerprints of numerous crucial biologic materials can be identified by terahertz (THz) spectroscopy, THz sensing have become an important approach of biological and medical detections. Particularly, benefit from the excellent capability of metasurface, strong interactions between the metasurface and THz waves can be realized, thus the THz sensing with high sensitivity becomes reality. However, the common configuration of metasurface-based THz sensor is composed of metallic subwavelength structure. Due to the inherent resistive loss of metal, it is still a great challenge to further enhance the quality factor (Q-factor) of resonance and sensitivity of THz sensor. In this work, we designed an all-dielectric metasurface with high Q-factor for highly sensitive THz sensors. The metasurface is a windmilllike structure consisting of four cuboids, and every adjacent two cuboids are arranged alternately vertically and horizontally. The transmission spectrum of metasurface exhibits four polarizationindependent and strong resonance peaks with high Q-factor in 0.1-2.5THz, and all of them show high sensitivity related to ambient refractive index. The transmitted structure and polarizationindependent resonances can relief the difficulty of measurement. We believe these studies will lay the theoretical and technical foundation for the design of high-sensitivity terahertz sensing.

Ultra-Narrowband High-Transmissivity Guided-Mode Resonance Filter Based on Dual Dielectric Film Structure and High Refractive Index Waveguide Layer

“…To accurately analyze the output spectrum of plane light perpendicular to a metal-grating, we employed finite-difference time-domain method, to simulate the waveguide grating structure. The normal Y-polarized [33], [34] incident light propagates along the negative Z-direction, i.e. TE polarization.…”

Emerging metasurfaces for refractometric sensing: fundamental and applications

“…Five works of metallic metasurfaces are presented in figure 1. Split-ring resonators (SRRs) are commonly used to obtain the desired characteristics, which is firstly proposed by Zhang et al [60]. Geng et al fabricate two kinds of gold metasurface biosensor integrated with microfluidics, which can be applied to detect the alpha fetoprotein (AFP) and glutamine transferase isozymes II (GGT-II) of liver cancer biomarker in early stage [61].…”

Flexible Metamaterial Quarter-Wave Plate and Its Application in Blocking the Backward Reflection of Terahertz Waves

“…In recent years, with the increasing maturity of terahertz technology, terahertz waves have been widely used in many application systems, such as terahertz detection [ 1 , 2 ], sensing [ 3 , 4 ], communication [ 5 , 6 ], and radar [ 7 , 8 ]. Especially in the application of 5G communication [ 9 , 10 ] and the technological development of 6G communication [ 11 , 12 ] in the future, terahertz communication technology has been widely considered by countries all over the world.…”