Pixelated Angle-Multiplexed Guided-Mode Resonance Metasurfaces for Broadband Terahertz Fingerprint Biosensing

• Published in: Photonics
• Main Authors: Weiqi Xu, Mengya Pan, Qiankai Hong, Shengyuan Shen, Conghui Guo, Yanpeng Shi, Yifei Zhang
• Format: Article
• Language: English
• Published: MDPI AG 2026-05-01
• Subjects: terahertz; guided-mode resonance; pixelated; fingerprint; broadband detection
• Online Access: https://www.mdpi.com/2304-6732/13/5/489

Terahertz (THz) fingerprint detection is central to identifying characteristic absorption fingerprints of biomolecules derived from their intrinsic rotational and vibrational modes. The development of guided-mode resonance (GMR) technology together with pixelated design offers a new approach to enhance the recognition capability of such fingerprint spectra. Here, a novel secondary grating metasurface based on cycloolefin polymer (COP) is proposed, which adopts an ultra-minimalist dual-pixel complementary architecture to excite high-quality (Q)-factor GMR. Its spectral resolution does not exceed 50 GHz, enabling precise capture of target molecular characteristic information and meeting the requirements of broadband fingerprint sensing. More importantly, the design regulates the dual-pixel grating units through parameter gradient optimization and incorporates a dual regulation mode of static pixel-targeted coverage and dynamic angle fine tuning. By adjusting geometric parameters and incident angles, broadband coverage from 1.15 THz to 2.20 THz is achieved, which can accurately match the multi-fingerprint detection requirements of glutamic acid (Glu) and glutamine (Gln). This metasurface sensor, integrating the advantages of pixelation and high-Q-factor GMR characteristics, provides an effective strategy for enhanced broadband THz fingerprint sensing and shows broad application potential in the field of biochemical trace detection.