Imaging and spectroscopy at terahertz frequencies have great potential for healthcare, plasma diagnostics, and homeland security applications. Terahertz frequencies correspond to energy level transitions of important molecules in biology and astrophysics. Terahertz radiation (T-rays) can penetrate clothing and, to some extent, can also penetrate biological materials, and because of their shorter wavelengths, they offer higher spatial resolution than microwaves or millimeter waves. We are developing hot electron bolometer (HEB) mixer receivers for heterodyne detection at terahertz frequencies. HEB detectors provide unprecedented sensitivity and spectral resolution at terahertz frequencies. We describe the development of a two-pixel focal plane array (FPA) based on HEB technology. Furthermore, we have demonstrated a fully automated, two-dimensional scanning, passive, imaging system based on our HEB technology operating at 0.85 THz. Our high spectral resolution terahertz imager has a noise equivalent temperature difference (NEDT) value of better than 0.5 K and a spatial resolution of a few millimeters. HEB technology is becoming the basis for advanced terahertz imaging and spectroscopic technologies for the study of biological and chemical agents over the entire terahertz spectrum.
Conference Dates: January 19-24, 2007
Conference Location: San Jose, CA
Conference Title: SPIE Photonics West
Pub Type: Conferences
focal plane arrays, heterodyne detectors, hot electron bolometers, quasi-optical systems, superconducting devices, terahertz imaging, terahertz receivers, terahertz spectroscopy