BIG LIGHT THROUGH LITTLE HOLES. Baffles with apertures smaller than the wavelength of a particular light wave aren't supposed to transmit much of that light. So it came as a surprise to Thomas Ebbesen at the NEC Research Institute in New Jersey when he shone light through sub-wavelength arrays (150-nm holes in a film of silver, coating a quartz substrate); at selected wavelengths, plentiful amounts of light (with wavelengths up to 10 times the size of the holes) came out the other side. Taking into account the area of the holes relative to the size of the light beam, the light was in some instances being transmitted with an efficiency of greater than 1. The leading explanation is that the light is making its way through the holes in the form (or with the assistance) of surface plasmons, non-radiating electromagnetic disturbances arising from the collective movements of electrons at conductor- insulator interfaces. The researchers believe that for device applications their arrays, which transmit light at special wavelengths, will complement so-called photonic crystals, which exclude light at special wavelengths. (Ebbesen et al., Nature, 12 Feb 1998.)