Lens allows optical microscopy down to 60 nanometers Results: A
team from the University of California, Berkeley, has devised a
silver “superlens” that could increase the resolution of light
microscopy by about a factor of six. The lens doesn’t diffract
light like conventional glass lenses. Instead, it uses
evanescent waves, which are produced when light hits a lens at
such an angle that it bounces off instead of passing through.
Evanescent waves emerge on the other side of the lens and add
optical information to normal “propagating” light waves, but
they decay very quickly over short distances. By capturing and
amplifying these weak waves, the researchers obtained images
with 60-nanometer resolution. Why it Matters: High-resolution
imaging methods such as electron microscopy can’t image living
tissue. Light microscopy can. Its resolution, however, is
limited by the wavelength of the light used. And 400 nanometers
is the shortest wavelength that doesn’t damage tissue.
Evanescent waves allow researchers to get