Nanoscale light-emitting device extends visbility of objects

July 15, 2015 // By Paul Buckley
University of Wisconsin-Madison engineers have developed a nanoscale device that claims to be able to emit light as powerfully as an object 10,000 times its size.

In a paper published in the journal Physical Review Letters, Zongfu Yu, an assistant professor of electrical and computer engineering, and his collaborators have described a nanoscale device that surpasses previous technology in its ability to scatter light. They showed how a single nanoresonator can manipulate light to cast a large reflection. The nanoresonator's capacity to absorb and emit light energy is such that it can make itself — and, in applications, other small things — appear 10,000 times as large as its physical size.

"Making an object look 10,000 times larger than its physical size has lots of implications in technologies related to light," said Yu. "This research opens up a new way to manipulate the flow of light, and could enable new technologies in light sensing and solar energy conversion".

The researchers realized the advance through materials innovation and an understanding of the physics of light. Much like sound, light can resonate, amplifying itself as the surrounding environment manipulates the physical properties of its wave energy. The researchers took advantage of this by creating an artificial material in which the wavelength of light is much larger than in a vacuum, which allows light waves to resonate more powerfully.

The device condenses light to a size smaller than its wavelength, meaning it can gather a lot of light energy, and then scatters the light across a large area, harnessing its output for imaging applications that make microscopic particles appear huge.

"The device makes an object super-visible by enlarging its optical appearance with this super-strong scattering effect," explained Ming Zhou, a Ph.D. student in Yu's group and lead author of the paper.