Number 132 (Story #2), June 10, 1993 by Phillip F. Schewe and Ben Stein VERTICAL CAVITY SURFACE EMITTING LASERS (VCSEL's) , lasers that emit light from the face of a semiconductor chip rather than from the cleft edge of the chip, now operate at visible wavelengths (as short as 631 nm) and can be powered with electricity instead of having to be pumped by another laser. The new VCSEL's, built by Richard Schneider and James Lott at Sandia, consist of numerous 10-nm layers of semiconductors which serve as quantum wells for trapping electrons and holes and as mirrors for reflecting and focusing light. Such surface-emitting, visible-light lasers on a chip are much more compact that the helium-neon gas lasers used in grocery-checkout scanners and generate light beams that are more focused (coming from through a 10-micron aperture) than the light beams from edge-emitting lasers on a chip. (Science News, 22 May 1993; Science, 28 May 1993.)