Sydney, Australia--A new lens for focusing terahertz radiation has a resolution of 1/28th wave, which is ten times the resolution of any previous terahertz lens; the wire-array metamaterial structure of the lens allows it to propagate near-field information (the result of capturing evanescent waves) over a distance of hundreds of wavelengths. Developed at the University of Sydney, the lens could be useful in areas of biophotonics research that include the medical and pharmaceutical arenas.
"This advance means we can unlock previously inaccessible information on the structure of molecules, their chemical make-up and the presence of certain proteins," says Alessandro Tuniz, lead author of a paper on the lens published in Nature Communications.1 "This opens up an entirely new tool for biological studies. It could allow earlier skin cancer diagnosis, because smaller melanomas can be recognized. For breast cancer, it can also be used to more accurately check that all traces of a tumor have been cut out during surgery."
The anisotropic metamaterial structure contains straight and tapered wire arrays made of plastic and metal; previously, such wire arrays were demonstrated only at much lower microwave frequencies. "The difficulty was making large quantities of matter structured on a micrometric scale," says Tuniz.
"The major challenge is making these materials on a scale that is useful," says Boris Kuhlmey, one of the researchers. "This is one of the first times a [terahertz] metamaterial with a real-world application, quickly able to be realized, has been feasible. Within the next two to three years, new terahertz microscopes that are ten times more powerful than current ones will be possible using our metamaterial."
In addition to seeing through some opaque materials, the lens can gather information on their chemical composition, and even get information on interaction between certain molecules, notes Tunis. This makes the lens well-suited to analyzing the delivery of drugs to cells, crucial in leading-edge medical research.
REFERENCE:
1. Alessandro Tuniz et al., Nature Communications 4, article no. 2706 (2013); doi:10.1038/ncomms3706.
