The Promise of Terahertz

Jan 16, 2005
Gwyn Williams holding an accelerator component inside JLab's FEL

Terahertz (THz) light may provide stunning breakthroughs in areas as diverse as national security, medical imaging and communications technology. But it's largely been ignored until recently, because there wasn't a terahertz light source bright enough for these applications. Now the Free-Electron Laser (FEL) at DOE's Jefferson Lab (JLab) is producing 100 Watts of THz light for scientific studies -- nearly 100,000 times brighter than THz light produced anywhere else.

Image: Gwyn Williams holding an accelerator component inside JLab's FEL.

Terahertz light is a little-studied realm of the electromagnetic spectrum between microwave and infrared light. Also known as t-rays, terahertz light has a wavelength between 3 millimeters and .003 millimeters; and though just about everything in the universe emits them, humans can neither see nor feel these ubiquitous t-rays.

FEL Basic Research Program Manager Gwyn Williams says scientists are excited about t-rays because they can penetrate many forms of matter and are non-ionizing (don't harm living tissue at modest powers). That means they may provide medical images that are better and safer than x-rays, such as a scanner that can instantly diagnose skin cancer. They could also be used for non-invasive airport screening, spotting weapons concealed in clothing.

Built with JLab's expertise in SRF technology, the FEL is the world's most powerful tunable laser. As electrons used to create the laser beam are steered from the linear accelerator around a curve to a wiggler where the laser beam is produced, the electrons give off t-rays. These t-rays can then be routed into a lab for research. “Every time there's an electron beam, we get terahertz,” Williams says. The project is funded by the U.S. Army Night Vision and Electronic Sensors Directorate.

Terahertz research can also extend JLab's mission of studying the structure of matter. For instance, Williams says t-rays can cause individual proteins to vibrate at specific frequencies, revealing structure. “It's also fundamental physics. But instead of looking at the atomic nucleus, we're looking at how materials work at the atomic level.”

Source: DOE Pulse

Explore further: A new, tunable device for spintronics

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

A new, tunable device for spintronics

9 hours ago

Recently, the research group of Professor Jairo Sinova from the Institute of Physics at Johannes Gutenberg University Mainz in collaboration with researchers from the UK, Prague, and Japan, has for the first time realised ...

Watching the structure of glass under pressure

9 hours ago

Glass has many applications that call for different properties, such as resistance to thermal shock or to chemically harsh environments. Glassmakers commonly use additives such as boron oxide to tweak these ...

Inter-dependent networks stress test

12 hours ago

Energy production systems are good examples of complex systems. Their infrastructure equipment requires ancillary sub-systems structured like a network—including water for cooling, transport to supply fuel, and ICT systems ...

Explainer: How does our sun shine?

13 hours ago

What makes our sun shine has been a mystery for most of human history. Given our sun is a star and stars are suns, explaining the source of the sun's energy would help us understand why stars shine. ...

User comments : 0