Subterahertz and Terahertz Sensing of Biological Objects and Chemical Agents

The applications of the terahertz (THz) technology include detection, sensing, and imaging of biological objects and chemical agents. The traditional approaches to sensing, and imaging of biological objects and chemical agents have been based on measuring THz absorption or reflection from biological tissues and compiling spectroscopic signatures of different chemicals. An extreme sensitivity of THz absorption and reflection to the water content allows for distinguishing cancer and healthy cells. Chemical changes, changes in polarizability or density or conformation might be detected as well. One of the limitations of the traditional THz absorption/reflection studies is related to a wavelength limited resolution. A more recent THz technology based on plasmonics and metamaterials has the resolution determined by the plasmonic detector feature size, i.e. down to the nanometer scale. Such detectors operating in a resonant regime are expected to have a large sensitivity at the plasma frequencies to even small changes of the dielectric properties at the detector surfaces. While remaining high-risk and high payoff technology, THz biological and chemical sensing is poised for breakthrough developments due to the recent progress in THz electronics including emerging nanoscale Si CMOS based sub-THz ICs.