The Center for Terahertz (THz) Research, under the leadership of Xi-Cheng Zhang, is having another very productive year, bringing in millions of dollars in funding, publishing groundbreaking research, and enhancing its international reputation for preeminence in the field.

Since January, more than $5 million in funding has been committed to the Center by government agencies, and applications have been submitted for an additional $10 million. In addition, the Center receives funding from industrial partners seeking to commercialize its research. Currently 13 companies support the THz center, and more than 70 companies have contacted the Center for possible collaborations.

Another sign of Rensselaer ’s preeminence in THz research is the number of lecture invitations received by Zhang, the J. Erik Jonsson ’22 Distinguished Professor, and other Center researchers. Zhang presents 20-30 invited lectures a year, and turns down scores more. He also chairs the new NATO Terahertz Exploratory Team, which held its first meeting at Rensselaer in January. The 20-member team of international experts is interested in using THz to detect hidden explosives. Zhang plans to hold a second NATO THz business meeting in September in Paris.

The THz Center, which directly reports to the School of Science, receives crucial support from the Physics department, Zhang said. Six faculty members are Center members: Zhang, the Center director; Michael Shur, the Patricia W. and C. Sheldon Roberts Professor; Gwo-Ching wang, chair of the Physics Department; Ingrid Wilke and Masashi Yamaguchi, assistant professors of physics; and Jingzhou Xu, research associate professor of physics. Zhang’s research group includes nine senior members and nine doctoral students, with a plan to hire more post docs.

At present, most of the Center’s funding comes from agencies interested in the defense and homeland security potential of THz sensing and imaging, Zhang said, He expects that picture to continue for two to three years, with biomedical applications becoming more important in five to 10 years.

The latest breakthrough for Zhang and his group, which will be featured in Laser Focus World, is the first use of ambient air as a sensor to detect pulsed THz waves. The research enables remote THz sensing even in high humidity, which was previously considered impossible because of high water vapor attenuation in the THz range. It also offers great flexibility in the choice of sensing locations. The paper describes a device in which a pulsed beam, generated by a femtosecond laser, is split and then focused  to create two areas of ionized air that serve as the emitter and the detector for THz waves.

Zhang and Yamaguchi have already received a commitment from the Office of Naval Research (ONR) for $900,000 to further explore this concept. In fact, three awards totaling $2.75 million have been committed by the ONR to Rensselaer’s THz research. Shur and Zhang have an award for $1 million for the THz detection of IEDs, and Xhang and Saroj Nayak, assistant professor of physics, have been funded for $700,000 to use modeling to improve understanding of the phonon signatures of explosives.

The THz Center also has three grants from the Homeland Security Advanced Research Project Agency in corporation with industry. Other current funding comes from the Army Research Office, the Army Benet Lab, NASA, and the Air Force Office of Scientific Research. The Center holds 14 patents, with more than 10 patents pending.

Zhang’s research group has designed and built portable THz wave imaging systems, which were tested and improved by NASA for the nondestructive testing of the foam insulation used on space shuttles. One compact THz imaging system was installed in NASA’s George Marshall Space Flight Center this year and another at Lockheed Martin. Recently, NASA’s Nondestructive Evaluation Science Branch contacted Zhang’s group, asking them to build more THz imaging systems for the NASA Kennedy Space Center and for NASA’s Langley Research Center .

Originally published May 2006 in the Rensselaer Research Update.

Published June 22, 2006