The laser edge
An ultraviolet, chip-based laser has been developed by Japanese scientists recently. Reports say that it is the shortest wavelength laser to be devised ever. This finding means that compact discs could be loaded with far more information than is thought to be possible at present. The device, developed by M Kawasaki and his team at the Tokyo Institute of Technology, Yokohama, uses thin, defect-free zinc oxide films that, when bombarded with light, re-emit the light in the form of an intense ultraviolet laser beam. The next step is to generate this type of laser with electric current, instead of bombarding the film light ( Science , Vol 276, No 5314).