New T-ray Tech Device Converts Light to Sound

Scientists have developed a new T-ray device that can essentially listen for light waves, opening up the doors to a part of the electromagnetic spectrum that up to this point, has been difficult to harness.

T-rays are light waves too long for the human eye to see, and are part of the terahertz range of the electromagnetic spectrum. By manipulating these types of light waves doctors could image body tissues without causing damage to healthy areas, for example, and it could give astronomers new tools for studying planets in other solar systems.

Exploration into these terahertz frequencies have been few and far between because specialized tools presently used to detect light are not capable of efficiently harnessing them.

Now, University of Michigan (U-M) researchers may have bridged that gap with their new technology.

"We convert the T-ray light into sound," U-M professor Jay Guo said in a news release. "Our detector is sensitive, compact and works at room temperature, and we've made it using an unconventional approach."

Guo and colleagues invented a special transducer that makes the light-to-sound conversion possible, though it produces a sound 1,000 times too high for humans to hear. A transducer turns one form of energy into another, and in this case it turns terahertz light into ultrasound waves and then transmits them.

Ultrasound detectors do already exist, but researchers made their own in the form of a microscopic plastic ring that's only a few millimeters in size. It also has a response speed of a fraction of a millionth of a second, which Guo says can enable real-time terahertz imaging in many areas.

"There are many ways to detect ultrasound," Guo said. "We transformed a difficult problem into a problem that's already been solved."

The details behind the technology were published May 22 in the journal Nature Photonics.