Polarization-Controllable High-Q Terahertz Metamaterial Sensor Based on an All-Liquid Crystal Polymer Platform for Multi-Parameter Sensing

Abstract

This work proposes a terahertz metamaterial sensor featuring polarization-controllable high-Q Fano resonances and multi-parameter sensing capability. The proposed metasurface is based on an all liquid crystal polymer (LCP) material and consists of periodically arranged cylindrical tetramers. Under x-polarized incidence, the sensor exhibits a high-Q resonance of 2126 at 1.701 THz, with a sensitivity of 91 GHz/RIU and a figure of merit (FOM) of 113.75 RIU⁻¹. Under y-polarized incidence, a Q-factor of 1629 is achieved at 1.466 THz, together with a sensitivity of 54 GHz/RIU and a FOM of 60 RIU⁻¹. In addition, this platform is innovatively combined with a multi-parameter sensing strategy, integrating x-polarized frequency shift, transmission variation, and dual-polarization frequency difference to enhance analyte discrimination and suppress common-mode interference. Based on this strategy, the sensor can achieve accurate discrimination and quantitative thickness detection of glutamine and isoleucine, two biomolecules with overlapping THz absorption peaks. This design provides an innovative approach for the highly sensitive and accurate detection of biomarkers. It promotes the application of THz sensing technology in clinical diagnosis and wearable fields.