Study Moves 'Superlens' Closer to Reality

CORVALLIS, Ore., Dec. 26 -- Physicists at Oregon State University say they have made an important advance toward the creation of a functional "superlens" -- an optical device that bends light differently than any natural material -- which could be used in applications such as electronics manufacturing, lithography and extreme levels of visual resolution.
A functional superlens would be a major breakthrough in optics and was first envisioned five years ago. The idea is to use exotic types of materials, proposed in the late 1960s, to create negative refraction of light, which literally means steering it in the opposite direction of that found in the natural world. The first materials that could do this were created a few years ago and the field is one of significant scientific interest, but researchers say many obstacles remain.

"In a conventional lens, light gets bent as it moves through a curved material, such as glass," said Viktor Podolskiy, an Oregon State assistant professor of physics and one of the authors of the study. "All natural materials have positive refraction, and if we could create a working lens with negative refraction, it would open up a whole new field of optical possibilities."

The new findings, by Podolskiy and student Nicholas Kuhta at Oregon State and University of Utah math professor and physicist Graeme W. Milton, successfully identified an optimal configuration for a superlens that would address the problem of bringing it into focus, a key problem up to this point. The research also maximizes the resolution of the superlens concept, at least twice as much as some other approaches. This research should make it more feasible to build a working superlens, Podolskiy said.

While the materials for extremely thin superlenses are readily available, larger devices require "artificial" materials -- extremely small particles that are combined in an array, acting as an optical magnet and a metal at the same time. Superlenses are designed primarily to see things more clearly with an extraordinary level of resolution, as opposed to conventional lenses that usually have a goal of magnification.

In theory, a superlens might be able to attain visual resolution at the level of the nanometer, or one billionth of a meter. A superlens, for instance, might find uses in electronics production, allowing machine vision systems to see and operate in much finer detail in the production of everything from semiconductors to DVDs. Being able to write and read smaller features could lead to much improved data storage. In biology, a superlens might be able to sense and visually photograph things at the molecular level. Improved radar and microwave transmission is also possible, experts say.

The research was supported by the National Science Foundation and was published under the title "Optimizing the superlens: Manipulating Geometry to Enhance the Resolution" in the Dec. 5 issue of the journal Applied Physics Letters.

For more information, visit: www.oregonstate.edu