THz Imaging: What You See and What you Don’t
Date & Time: Tuesday, January 21, 2014, 10:10 AM – 11:50 AM
THz technology has developed to the point at which we can now begin to use customized-off-the-shelf components to construct near-real time imagers. However traditional imaging at these wavelengths is extremely challenging. Most materials, and the atmosphere itself, have extremely high loss, limiting transmission measurements. Contrast from scattered energy is generally low, as the frequency and amplitude sensitivity to reflected power from most environmental objects is poor. Thermal contrast is limited by high background temperatures (generally above the energy range of THz signals). However, as advances in solid-state source and receiver technology push ever upwards in frequency, more and more proposals are aimed at using this new found capability for active and passive imaging. It turns out that there are at least a few tricks that one can play to help integrate millimeter and submillimeter wavelength transceivers into traditional imaging applications. One of the first application areas to take advantage is undergarment threat detection.
This talk will discuss current techniques in active THz scanning, both to introduce the phenomenology of what we see reflected off the body, as well as the hidden phenomenology of what THz radiation may be stimulating in the body
Peter H. Siegel (BA Colgate 1976, PhD Columbia, 1983, IEEE member since 1975) has held appointments as Faculty Associate in Electrical Engineering and Senior Scientist in Biology at Caltech and Senior Research Scientist at the NASA Jet Propulsion Laboratory. At JPL, he founded and led for 20 years, the Submillimeter Wave Advanced Technology (SWAT) team, a group of 20+ scientists and engineers developing THz technology for NASA’s near and long term space missions. This included delivering key components for four major satellite missions and leading more than 75 smaller R&D programs for NASA and the US department of defence. At Caltech, Dr. Siegel has been involved in new biological and medical applications of THz, especially low power effects on neurons and most recently, millimetre-wave monitoring of blood chemistry. Among many other functions, he serves as founding Editor-in-Chief of the IEEE Transactions on Terahertz Science and Technology and the General Secretary of the International Society of Infrared, Millimeter, and Terahertz Waves, the world’s largest society devoted exclusively to THz science and technology, which he founded in 2009. He is also an IEEE Fellow, and has served as an IEEE Distinguished lecturer, vice-chair and chair of IEEE MTTS Committee 4 – THz Technology, and an ad-hoc member of the MTTS AdCom. Dr. Siegel has published more than 300 articles on THz components and technology and has given more than 100 invited talks on this subject throughout his career of 37 years in THz.