Sharper than expected

A new technique beats the resolution limits of ordinary microscopes in a way that seems to defy conventional optical theory, its discoverers say.

Peter Stark of Harvard Medical School in Boston and his collaborators exposed a photosensitive film to light coming from microscopic holes in a thin silver plate. Ordinarily, those images would record no details smaller than half the wavelength of light, a fact that limits the resolution of optical microscopes to about 200 nanometers.