By constructing artificial materials that break long-standing rules of nature, a University of Toronto researcher has developed a flat lens that could significantly enhance the resolution of imaged objects. This, in turn, could lead to smaller and more effective antennas and devices for cell phones, increased space for data storage on CD-ROMs and more complex electronic circuits.
"This is new physics," says George Eleftheriades, a U of T professor specializing in electromagnetic technology at the Edward S. Rogers Sr. Department of Electrical and Computer Engineering and senior author of an article in the March 24 issue of Applied Physics Letters. "These findings provide an opportunity to resolve details in an object smaller than a wavelength."
The team works in the rapidly emerging field of metamaterials - artificially created substances with properties not found in nature. Under normal electromagnetic conditions, light passing through a flat lens will diverge; light passing through a lens made of metamaterials, however, will bend the "wrong" way and become focused.
Their study reveals that when evanescent waves - weak but important waves that lose strength quickly after leaving their source - are directed through their flat metamaterial lens, these waves are amplified. At the same time, the lens corrects the phase of the waves by focusing the diverging waves into a beam. Metamaterial lenses, when constructed at optical frequencies, could be used to engineer the next generation of electronic devices at the nanometre scale, says Eleftheriades.
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