Nichia Corp. said Monday it will begin commercial production next April of high-powered violet laser diodes indispensable for the development of next-generation DVDs.

Generating 30 milliwatts of laser light, the diode can not only read data from but also write data to DVDs, the maker of the light-emitting diodes said.

Current violet laser diodes, which Nichia has been producing since October 1999, only read data, as they generate only 5 milliwatts of laser light.

Digital signals stored on DVDs are retrieved by applying laser light. While red laser light is currently used, violet laser light has a shorter wavelength and can thus handle signals of higher density, the company said.

Next-generation DVDs will be capable of storing five times more data than current DVDs and can record nearly 10 hours of television-quality images.