August 30, 2005
By: Charlie Feigenoff
Communications
companies regularly spend billions of dollars for small
portions of the electromagnetic spectrum, yet they wouldn't
pay a dime for the large range of frequencies, between 100
gigahertz and 10 terahertz, in the terahertz range. This
may soon change. Work being done by engineers at the University
of Virginia could transform this neglected area of the spectrum
into valuable real estate.
On the face of it, this might seem foolhardy. For one thing, terahertz signals don’t penetrate very far into the atmosphere, making them poor candidates for wireless communications. And since the frequencies sit on the border between electronics and photonics, making terahertz devices can be tricky.
But terahertz signals are ideal for astronomical observations—and U.Va. has scored a number of early breakthroughs in developing terahertz detectors for radio telescopes and satellites. “Most of the photons in the universe fall into the terahertz range,” notes U.Va. engineer Robert Weikle. “Analyzing terahertz radiation is critical in helping astronomers gain a better understanding of how stars form.” Working with scientists at the National Radio Astronomy Observatory, U.Va. engineers have helped develop the terahertz sensors used in the 64 antennas that make up the groundbreaking Altamira Large Millimeter Array project at 16,000 feet in Chile.
Weikle and others have received a grant from the W.M. Keck Foundation to establish the Foundation’s Center for THz Spectroscopy for Biological Materials. Weikle, Thomas Crowe, Tatiana Globus and Boris Gelmont of the Charles L. Brown Department of Electrical and Computer Engineering; Donald Brown (PI) and Michael DeVore of the Systems and Information Engineering Department; Lukas Tamm of the Molecular Physiology and Biological Physics Department; and a team of graduate students will work to develop a device for using the terahertz spectrum to study biological molecules.
Different biological materials have unique signatures in the teraherz range. Applications for the device may include terahertz sensors to identify skin cancer.
