Metamaterials demonstrated negative refractive index and up until that point the commonly held belief was that only a positive index was possible, said Padilla. Metamaterials gave us access to new regimes of electromagnetic response that you could not get from normal materials.
Prior research has shown that because they rely on light-driven resonance, metamaterials experience frequency dispersion and narrow bandwidth operation where the centre frequency is fixed based on the geometry and dimensions of the elements comprising the metamaterial composite. The team believes that the creation of a material that addresses the narrow bandwidth limitations can advance the use of metamaterials.
Enormous efforts have focused on the search for materials that could respond to terahertz radiation, a scientific quest to find the building blocks for devices that could take advantage of the frequency for imaging and other applications.
Potential applications could lie in medical imaging or security screening, said Padilla. Materials undetectable through x-ray scans such as chemicals, biological agents, and certain explosives can provide a unique fingerprint when struck by radiation in the far-infrared spectrum. Metamaterials like the one developed by the research team will facilitate future devices operating at the terahertz frequency of the electromagnetic spectrum.
In addition to imaging and screening, researchers and high-tech companies are probing the use of terahertz in switches, modulators, lenses, detectors, high bit-rate communications, secure communications, the detection of chemical and biological ag
|Contact: Ed Hayward|