Imaging-based terahertz pixelated metamaterials for molecular fingerprint sensing

With the rapid development of terahertz-enabled devices, the study of miniaturized and integrated systems has attracted significant attention. We experimentally demonstrate an imaging-based pixelated metamaterial for detecting terahertz molecular fingerprints related to intermolecular vibrations and large-amplitude intramolecular modes, including chemical identification and compositional analysis. The compact THz sensor consists of a 4 × 4 pixelated filter-detector array with transmission resonances tuned to discrete frequencies. The absorption spectra of analytes are computationally reconstructed from different spectral responses of meta-pixels, and the resulting information is characterized via near-field imaging. Due to the spectrometer-less operation principle, such imaging-based approaches provide an alternative method for developing sensitive, versatile, and miniaturized THz biosensors, especially for practical field deployment applications.