Physicists at Oregon State University have made an important advance towards the creation of a functional “superlens” – an extraordinary optical device that would bend light the opposite direction of that done by any natural material.
The device would have a wide range of possible applications in electronics manufacturing, lithography, extreme levels of visual resolution, and many other uses. The new findings, which will bring the superlens concept several important steps closer to working reality, were just published in a professional journal, Applied Physics Letters.
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 many obstacles remain.
“In a conventional lens, light gets bent as it moves through a curved material, such as glass,” said Viktor Podolskiy, an OSU assistant professor of physics. “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 OSU findings successfully identified an optimal configuration for a superlens that would address the problem of bringing a superlens into focus, a key problem 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, which is pretty small – a human hair is about 100,000 nanometers wide.
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.
These studies were supported by the National Science Foundation.