High-sensitivity and multiple fingerprint detection at an exception point in electromagnetic induced transparent metasurfaces

Electromagnetic induced transparent (EIT) metasurfaces have garnered significant interest in the terahertz (THz) fingerprint sensing field, owing to their capability to enhance light-matter interactions. However, previous EIT metasurfaces typically exhibit unsatisfactory sensitivity and a narrower detection bandwidth, limiting their capability in broadband fingerprint detection. Here, an EIT metasurface characterized by exceptional point and tunable properties is presented. Based on the synchronous gate voltage tuning, this EIT metasurface demonstrates tunability in the range of 2.6–4.1 THz, which facilitates the acquisition of multiple fingerprint from analytes. And through theoretical calculations, the exceptional point was accurately identified, enabling the EIT metasurface to achieve a sensitivity of 1.22 THz/RIU. Most importantly, the proposed EIT metasurface identifies multiple THz fingerprints of melamine, showcasing a excellent capability for fingerprint sensing. The proposed EIT metasurface integrates high sensitivity and tunability, showcasing significant potential for applications in broadband THz fingerprint sensing.