The recent availability of GaN-based laser diodes, nurtured by a strong and flourishing LED market, has opened up a host of new applications. The optical storage market, essentially the raison d'étre for this technology, is leading the way with a new generation of writers/players that build upon established optical storage technology. The two contenders for a new storage format, the recently standardized Blu-ray Disc,¹ proposed by the 10-strong, similarly named consortium, and AOD,² proposed by Toshiba and NEC, both utilize 405-nm laser diodes but differ in the extent of their departure from the optics configuration for DVD. The expected storage capacities on a CD-size disc are approximately 25 and 15 GB, respectively.

Nichia Corp.'s much-publicized techno-legal wrangles with other laser diode manufacturers have receded significantly, and in the meantime, the technology has progressed. On the one hand, to satisfy the requirements for double- and quadruple-speed drives, laser diode manufacturers project pulsed or even CW output powers up to 100 mW at 405 nm for 2004 or 2005, while on the other hand, sample laser diodes emitting around 375 nm (UV) and 440 and 470 nm (both blue) have been issued to technology leaders.³..