Search Menu
Photonics Media Photonics Buyers' Guide Photonics EDU Photonics Spectra BioPhotonics EuroPhotonics Industrial Photonics Photonics Showcase Photonics ProdSpec Photonics Handbook
More News
Email Facebook Twitter Google+ LinkedIn Comments

Magnetized Common Metals Refract Negatively
Aug 2011
VIENNA, Austria, Aug. 19, 2011 — While it is generally believed that negative refraction cannot be achieved with natural materials, scientists at the Vienna University of Technology (TU Vienna) report that when common metals such as cobalt and iron are placed in a magnetic field, they too are capable of a negative refractive index.

The effect of negative refraction can be seen in nature when a stick, for example, is partly submerged in water. At the surface, the light changes its direction, and the stick appears to be bent at the interface between the air and water. For years, scientists have tried to mimic this negative refractive index, believing that these effects could be achieved only using metamaterials. Such materials, constructed from small, intricate structures, would diffract the light in special ways on a microscopic level.

The beam of light enters the metal and is refracted into the opposite direction (left) compared to the usual behavior of light in materials (right). (Image: Vienna University of Technology)

At TU Vienna, scientists found that with simple tricks, even quite common metals can exhibit a negative refractive index. “We place the metal in a strong magnetic field and irradiate it with light of precisely the correct wavelength,” said Andrei Pimenov, a professor at TU Vienna. He used microwave radiation, which can penetrate thin foils of metal. Due to magnetic resonance effects in the metal, the light is bent drastically at the surface. Within the metal, the light turns in the other direction as if there were a mirror there.

Scientists believe that this could lead to completely new optical effects and technologies.

Recently, materials with a negative diffractive index have attracted a great deal of attention, because their peculiar behavior could allow for completely new kinds of optical lenses. The resolution of regular lenses is limited by the wavelength of light.

“But using a material with a negative refractive index, one could theoretically get infinitely high resolution,” Pimenov said. Being able to use simple metals instead of complicated metamaterials makes things a lot easier. However, before optical lenses with a negative refractive index can be built, scientists have to find ways to compensate for the absorption of the light in the material, he said.

For more information, visit:

Andrei PimenovAustriaBasic Sciencecobaltdiffract lightEuropeironlenseslight sourcesmagnetic fieldmetamaterialsmicrowave radiationmirrorsnegative refractive indexopticsResearch & TechnologyTU ViennaVienna University of Technology

Terms & Conditions Privacy Policy About Us Contact Us
back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2018 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA,

Photonics Media, Laurin Publishing
x We deliver – right to your inbox. Subscribe FREE to our newsletters.
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.