Crystal Light; September 1993; Scientific American Magazine; by W. Wayt Gibbs; 2 Page(s)

In July, IBM announced that its researchers had packed five times the usual amount of data onto an optical disk by shortening the wavelength of their laser's light from infrared to blue. That achievement is as much an ending as a beginning. Further progress in CD-ROM technology faces a fundamental limit: the pits that encode information on the surface of a compact disc can be no smaller than the wavelength of the laser light used to read them. The next giant leap in data density will have to come from elsewhere.

A handful of scientists around the world think it might come from crystals that can remember and reproduce patterns and colors of light. Where compact discs store data in two dimensions, these crystals make use of four: volume and color, as well as area. Crystal storage pioneers believe the technology has cleared its theoretical hurdles and entered the race to succeed current optical and magnetic memories.