Nichia, Matsushita to shi¥blue lasers

Nichia, Matsushita to shi¥blue lasers

Nichia Chemical Industries Ltd. (Tokushima, Japan) and Matsushita Electric Industrial Co. Ltd. (Osaka, Japan) are planning to shi¥samples of blue-violet-emitting laser devices with wavelengths of 410 nm by the end of 1998. Practical blue-violet diode lasers, however, are not expected to be available until early in the 21st century. Nichia Chemical is working on a gallium nitride-based diode laser, while the Matsushita Electric design is a second-harmonic-generation device, combining a red-emitting diode laser with an optical waveguide, yielding a blue-violet laser beam. Both firms are setting their sights on the rewritable optical-disk-drive market. Currently, neither laser fully satisfies the requirements for use in rewritable optical-disk drives. Both Nichia Chemical and Matsushita Electric claim they will offer optical power levels of 20 to 30 mW, which is sufficient for a rewritable optical disk, by the end of 1998. No one, however, has achieved this power level yet.