CHESTNUT HILL, MA (February 24, 2009) An engineered metamaterial proved it can function as a state-of-the-art device in the complex terahertz range of the electromagnetic spectrum, setting a standard of performance for modulating tiny waves of radiation, according to a team of researchers from Boston College, the Los Alamos and Sandia national laboratories, and Boston University.
An electrical current applied to the metamaterial a hybrid structure of metallic split-ring resonators controlled the phase of a terahertz (THz) beam 30 times faster and with far greater precision than a conventional optical device, the researchers report in the current online edition of the journal Nature Photonics.
The discovery marks a milestone in the use of metamaterials and terahertz radiation, a safe, non-ionizing frequency that is the subject of a growing body of research and viewed as a promising component in applications that include advanced security screening systems and imaging technologies.
"This is a true metamaterial device," Boston College Asst. Prof. of Physics Willie J. Padilla, one of the co-authors of the paper, said. "This highlights the fact that you can make solid state devices at terahertz frequencies with metamaterials."
Constructed on the micron-scale, metamaterials are composites that use unique metallic contours in order to produce responses to light waves, giving each metamaterial its own unique properties beyond the elements of the actual materials in use. Within the past decade, researchers have sought ways to significantly expand the range of material responses to waves of electromagnetic radiation classified by increasing frequency as radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. These metamaterials have demonstrated numerous novel effects that defy accepted electromagnetic principles.
Previously, in systems known as
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