Peter H. Siegel

Visiting Associate: Engineering and Applied Science
Senior Scientist Emeritus: Division of Biology (11 years)
Senior Research Scientist:
Jet Propulsion Laboratory (26 years)
Founder: JPL Submillimeter Wave Advanced Technology (SWAT)

Founder/CEO of THz Global, an international collaborative research consulting team working on a wide variety of THz research and applications

Founder, International Society of
Infrared, Millimeter, and Terahertz Waves

Founding Editor-in-Chief, IEEE Transactions on
Terahertz Science and Technology

B.A. Astronomy, 1976, Colgate University, Hamilton, NY
M.S. Physics, 1978, Columbia University, NY
Ph.D. Electrical Engineering, 1983, Columbia University, NY

Email contact phs AT caltech DOT edu

Research in Terahertz Technology and Applications: Earth and Space Science, Biology, Medicine, Defense and related Civilian opportunities

To view Dr. Siegel's current research and his former research group .

Link to the International Society of Infrared, Millimeter and Terahertz Waves

Link to the Kenneth J Button Prize Nomination Form

Link to the IRMMW-THz Society Youbng Scientist Award Form

Link to 39th International Conference on Infrared, Millimeter and Terahertz Waves held at University of Arizona, Tucson from September 14th-19th, 2014.

Link to 33rd International Conference on Infrared, Millimeter and Terahertz Waves held at Caltech from September 15-19, 2008.

Link to IEEE Transactions on Terahertz Science and Technology   THZ Journal
If you wish to be considered for review board membership or to help out with the THz journal in any way please email Peter Siegel  

Background and Philosophy: Dr. Siegel’s research specializes in the invention, development and delivery of a wide range of specialized sensor and source devices, components, and instruments spanning the frequency range between 100 and 10,000 GHz which includes the millimeter, submillimeter and far infrared wavelength regimes: the terahertz bands. Emphasis is placed on a cross disciplinary approach which brings together a diverse range of backgrounds and skills that can be directly applied towards progress in bridging the electronic and optical regimes, one of the last remaining technology gaps in the electromagnetic spectrum. Students and staff working with Dr. Siegel include electrical engineers, physicists, biologists and chemists from a wide range of backgrounds and countries. Research work is conducted both at Caltech and at the nearby Jet Propulsion Laboratory, where the emphasis is on Earth, space science and planetary applications of THz technology. Dr. Siegel has recently founded a small international consulting company, THz Global, through which he is continuing his THz research work in collaboration with an international team of colleagues with expertise that spans the full range of millimeter and submillimeter wave applications.

Over the past 26 years Dr. Siegel and his Submillimeter Wave Advanced Technology team at JPL and Caltech have developed and delivered critical sensor hardware for four space flight missions: NASA’s Upper Atmospheric Research Satellite Microwave Limb Sounder, the first instrument to directly measure the anti-correlation between chlorine monoxide build up and ozone depletion on a global scale; NASA’s Earth Observing System Aura Microwave Limb Sounder measuring a wide range of stratospheric molecular species involved in ozone depletion, global water distribution, climate change and pollution monitoring across the Earth and carrying the first THz heterodyne radiometer in space - 2.5 THz OH and water line receiver; the European Space Agency’s Microwave Instrument on the Rosetta Orbiter (MIRO), that recently rendezvoused with comet Churyumov-Gerasimenko and that measures nuclear temperature and out gassing rates of carbon monoxide, water, ammonia and methanol; and most recently the Heterodyne Instrument for the Far Infrared (HIFI) on the European Space Agency’s Herschel Space Telescope, an ambitious astrophysics mission recording thousands of molecular signatures between 300 and 1900 GHz in and around star forming regions and in external galaxies, as a means of understanding the composition and evolution of the universe.

In addition to Earth, planetary and space science, Dr. Siegel is interested in terrestrial applications of terahertz imaging and spectroscopy and has been actively pursuing several related initiatives in the health and biological sciences at Caltech as well as defense and security applications at both Caltech and JPL. The very first National Institute of Health program in the terahertz field, granted to Dr. Siegel in 2002, had the goal of developing high signal-to-noise imaging and spectroscopy instruments for disease diagnostics. A second THz NIH program to develop low loss terahertz waveguide for endoscopy applications has also been completed. Additional work on the thermal and non- thermal effects of millimeter and submillimeter-wave radiation on cellular systems was started in 2008. This work was undertaken in conjunction with the Caltech biology division and a neurophysiologist, Dr. Victor Pikov, then at the Huntington Medical Research Institute in Pasadena, California. Significant expansion of the biological science work at Caltech included work on rats, leeches, zebra fish and oocytes to look at low power millimeter-wave stimulation and control of neuronal responses, which included a collaboration with Francisco Bezanilla and Michael Priest at Univ. of Chicago and Mikhail Shapiro, now at Caltech. Most recently work has focused on the use of millimeter waves for direct medical applications. Three ongoing tasks include non-invasive glucose monitoring using millimeter-wave transmission; non-invasive determination of blood bag spoilage (a collaboration with Yuri Feldman and colleagues at Hebrew University; and a new program to incorporate and utilize millimeter-wave hyperthermia in a commercial MRI system (a collaboration with HMRI).


Dr. Siegel is working in the Millimeter-Wave Bioapps Lab in 108 Moore where he has epi-fluorescence inverted and upright microscopes, an incubator, and an RF exposure system for studying cell level responses and processes. He also has a well equipped RF and bio lab at THz Global - his small business located in La Canada, California. Dr. Siegel regularly accesses the Huntington Medical Research Institute animal facilities across from Huntington Hopsital, Pasadena, where he works with Dr. Marie Csete, HMRI Director and Chief Scientist as well as other staff members, on millimeter wave bio applications. He frequently consults with and visits with former colleagues and friends from the JPL Submillimeter-Wave Advanced Technology team, which he founded in 1992, and which is currently managed by Dr. Imran Mehdi.

Recent and review papers describing current work: