基于全介质超表面高Q的双带太赫兹传感器

High-Q Dual-Band Terahertz Sensor Based on All-Dielectric Metasurface

设计了一种由连续域束缚态控制的高灵敏度太赫兹折射率传感器。该传感器由全介质光栅构成,通过平移打破结构的对称性,可以将共振转变为高品质因子(Q因子)泄漏模共振,且线宽极窄腔模式对周围介质的折射率变化非常敏感。利用有限元方法,数值模拟了具有不同非对称参数、光栅厚度、光栅宽度以及折射率分析物的透射光谱。结果表明,该光栅超表面的Q因子达到12620,标准灵敏度为31395 nm/RIU,FOM(Figure of merit)为1000,在太赫兹范围内的高灵敏光子传感器领域具有潜在的应用。

A high-sensitivity terahertz refractive index sensor controlled by the continuum bound state is designed in this paper.The sensor is composed of all-dielectric grating.By breaking the symmetry of the structure by translation,and the resonance can be transformed into a leakage mode resonance with a high quality factor(Q factor),and the extremely narrow linewidth cavity mode is very sensitive to the change of the refractive index of the surrounding medium.Using the finite element method,the transmission spectra with different asymmetry parameters,grating thickness,grating width,and refractive index of analytes are numerically simulated.The results show that the Q factor of the grating metasurface reaches 12620,the standard sensitivity is 31395 nm/RIU,and the FOM(Figure of merit)is 1000.The structure has potential applications in the field of highly sensitive photon sensors in the terahertz range.