John A. Paulson School of Engineering and Applied Sciences/Harvard University
A titanium dioxide metamaterial lens
It might be small, but it s a big feat.
In a normal lens, a curved glass surface a few millimetres or even centimetres thick redirects light rays to a common focal point.
To improve the image – say, to take out distortions, or make sure different wavelengths of light all get focused correctly – you have to keep adding glass layers.
As a result, cameras, microscopes and telescopes are limited in part by the size and heft of the lenses they require.
Using a beam of electrons, the team carved nanofins – 600-nanometre-tall blocks that together resemble the world s smallest Stonehenge – out of a block of titanium dioxide.
Each could focus light more sharply than a 55-millimetre-thick Nikon microscope lens with similar optical properties – even though the 600-nanometre-thick metamaterial lens was 100,000 times thinner than the Nikon.