A Terahertz Microscopy Technique for Sweat Duct Detection

We propose a THz imaging technique that uses high reflective index optics to improve spatial resolution and enable a novel biometrics imaging tool. Specifically, with the use of THz waves we can penetrate the drier outer skin layers and provide anatomical information on the skin's layered morphology and the underlying structures (e.g. sweat ducts). Sweat ducts are subcutaneous helical structures that exhibit absorption in the sub-THz frequency range. The proposed THz microscopy configuration can acquire high spatial resolution images of the human skin and classify sweat ducts based on the backscattered THz spectrum. In this paper, the theoretical background of the microscopy technique and the experimental design are discussed. Finally, THz images of human fingerprints are presented, verifying the imaging capabilities of the proposed configuration.