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

Metamaterials Display Negative Phase and Group Velocity

Photonics Spectra
Jun 2006
A team made up of researchers in Europe and the US has confirmed that negative-refractive-index media also can exhibit exotic pulse propagation phenomena. In the May 12 issue of Science, the investigators from Universität Karlsruhe and Forschunszentrum Karlsruhe in der Helmholtz-Gemeinschaft, both in Germany, from Iowa State University in Ames, and from the University of Crete in Iraklion, Greece, present the findings of experiments with metamaterials that simultaneously display a negative phase velocity and a negative group velocity at 1500 nm.


For their work, the scientists used electron-beam lithography and evaporation techniques to fabricate 60 metamaterial samples constructed from two 25-nm-thick gold films sandwiching a 35-nm-thick MgF2 spacer layer and atop glass substrates coated with ITO. By inserting a sample into one arm of a Michelson interferometer into which they injected 170-fs pulses of 1500-nm radiation from an optical parametric oscillator, they deduced from the effects on the interference fringes that the metamaterials have a negative phase and group velocity such that both the carrier wave and peak of a given pulse exit the samples before they have entered.

Terms & Conditions Privacy Policy About Us Contact Us
back to top

Facebook Twitter Instagram LinkedIn YouTube RSS
©2016 Photonics Media
x Subscribe to Photonics Spectra magazine - FREE!