A Solid-State 0.56 THz Near-Field Array for μM-Scale Surface Imaging

We demonstrate a fully-integrated 0.56 THz 128-pixel near-field 1-D sensor array with 10-12 μm lateral resolution. The sensing elements are based two parallel cross-bridged split-ring resonators that utilize a 3-D topology to exhibit high field confinement in the sensing spot. The sensor comprises a scalable excitation scheme that is designed to maximize the fill factor of the imager for large 1-D arrays. The THz front-end is co-integrated with a digital-read out chain. This enables rapid THz near-field image acquisition of planar and soft surfaces. Furthermore, the imager can be operated as a standalone device that is only powered with a USB cable. As an exemplary application, this work demonstrates THz near-field sensing as a tool for biometric fingerprint reading for the first time.