WEST LAFAYETTE, Ind. - Researchers are developing a new class of "plasmonic metamaterials" as potential building blocks for advanced optical technologies, including ultrapowerful microscopes and computers, improved solar cells, and a possible invisibility cloak.
The new materials could make possible "nanophotonic" devices for numerous applications, said Alexandra Boltasseva, an assistant professor of electrical and computer engineering at Purdue University.
Unlike natural materials, metamaterials may possess an index of refraction less than one or less than zero. Refraction occurs as electromagnetic waves, including light, bend when passing from one material into another. It causes the bent-stick-in-water effect, which occurs when a stick placed in a glass of water appears crooked when viewed from the outside.
Being able to create materials with an index of refraction that's negative or between one and zero promises a range of potential breakthroughs in a new field called transformation optics. However, development of new technologies using metamaterials has been hindered by two major limitations: too much light is "lost," or absorbed by metals such as silver and gold contained in the metamaterials, and the materials need to be more precisely tuned so that they possess the proper index of refraction.
Optical nanophotonic circuits might harness clouds of electrons called "surface plasmons" to manipulate and control the routing of light in devices too tiny for conventional lasers.
Some of the new materials are showing promise in uses involving near-infrared light, the range of the spectrum critical for telecommunications and fiberoptics. Other materials also might work for light in the visible range of the spectrum. The new materials might be tuned so that their refractive index is ideal for specific ranges of the spectrum, allowing their use for particular applications.
Future photonics technologies will revolve around new types of optical transistors, switches and data processors. Conventional computers transmit and process pieces of information in serial form, or one piece at a time. However, future computers may use parallel streams of data, resulting in much faster networks and computers.
The work has been funded by the U.S. Army Research Office. Writer: Emil Venere, 765-494-4709, firstname.lastname@example.org Source: Alexandra Boltasseva, 765-494-0301, email@example.com Related website: Alexandra Boltasseva: engineering.purdue.edu/ECE/People/profile
Contact: Emil Venere firstname.lastname@example.org 765-494-4709 Purdue University