Angle-Dependent Metasurface for Nonspectroscopic THz Sensing of Submicrometer Films

• Published in: IEEE sensors journal Vol. 23; no. 22; pp. 27262 - 27272
• Main Authors: Tumashov, Maksim A., Baena, Juan D., del Risco, Juan P., Lazorskiy, Pavel A., Glybovski, Stanislav B., Kuznetsov, Sergei A.
• Format: Journal Article
• Language: English
• Published: New York IEEE 15-11-2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Frequency ranges; Impedance; Incidence angle; Metasurface (MS); Metasurfaces; Mirrors; Resonant frequency; sensing; Sensors; Surface impedance; Surface waves; terahertz (THz); Thick films; Thin films; thin-film
• ISSN: 1530-437X; 1558-1748
• DOI: 10.1109/JSEN.2023.3319955

Efficient sensors for terahertz (THz) frequency range are in high demand for applications in biomedicine, chemistry, security, and electronics. Conventional thin-film sensing relies on spectroscopy, while improved sensitivity can be achieved using frequency selective electromagnetic metasurfaces (FSMSs). A simpler and innovative approach involves a nonspectroscopic method using a single-frequency THz source and an angle-dependent metasurface (MS) under oblique illumination. This method derives analyte parameters from the shift in the resonant transmission angle. We further develop this platform and investigate a new MS operating at 0.139 THz, exhibiting a strong variation of a narrow stopband with the angle of incidence. Theoretical, numerical, and experimental results demonstrate the MSs ability to detect submicrometer-thick films. The proposed nonspectroscopic sensing technique offers a promising avenue for highly efficient and sensitive detection of dielectric thin films.