A terahertz lens
Researchers have
used an array of stacked plates to make a lens for terahertz radiation.
The technique
could set stage for new types of components for manipulating terahertz waves.
Mittleman lab /
Brown University
(March 14, 2016) Brown
University engineers have devised a way to focus terahertz radiation using an
array of stacked metal plates, which may prove useful for terahertz imaging or
in next-generation data networks.
Terahertz radiation is a relatively unexplored slice of the
electromagnetic spectrum, but it holds the promise of countless new imaging
applications as well as wireless communication networks with extremely high
bandwidth. The problem is that there are few off-the-shelf components available
for manipulating terahertz waves.
Now, researchers from Brown University’s School of
Engineering have developed a new type of lens for focusing terahertz radiation
(which spans from about 100 to 10,000 GHz). The lens, made from an array of
stacked metal plates with spaces between them, performs as well or better than
existing terahertz lenses, and the architecture used to build the device could
set the stage for a range of other terahertz components that don’t currently
exist.
The work was led by Rajind Mendis, assistant professor of
engineering (research) at Brown, who worked with Dan Mittleman, professor of
engineering at Brown. The work is described in the journal Nature Scientific
Reports.
The image shows a
a two-centimeter beam focused to four millimeters.
Mittleman lab /
Brown University
“Any photonic system that uses terahertz – whether it’s in
imaging, wireless communications or something else – will require lenses,” said
Dan Mittleman, professor of engineering at Brown and the senior author on the
new paper. “We wanted to look for new ways to focus terahertz radiation.”
Most lenses use the refractive properties of a material to
focus light energy. Eyeglasses, for example, use convex glass to bend visible
light and focus it on a certain spot. But for this new terahertz lens, the
properties of the materials used don’t matter as much as the way in which the
materials are arranged.