EVERY lens made has been limited by the wavelength of the light it focuses. Until now. Canadian engineers have made the first 鈥減erfect lens鈥�, which can focus features smaller than the wavelength of the light itself.
John Pendry of Imperial College, London, suggested in 2000 that such a lens might be built using so-called left-handed materials, which refract light in the opposite direction to normal. Such a material would amplify waves that carry information about features smaller than the wavelength of the radiation. Normally, these 鈥渆vanescent鈥� waves are too weak to make it through a regular lens. Left-handed materials have since been built, but no one was able to create a perfect lens from them.
Now George Eleftheriades of the University of Toronto and colleagues have built one using a mesh of copper strips embedded with capacitors and inductors. The capacitors and inductors interact with microwaves in such a way that the grid acts as a left-handed material at these frequencies. When the researchers shone microwaves on the grid, it amplified and focused the evanescent waves (Physics Review Letters, vol 92, p 117403).
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