Lasers for recordable DVD. From blue to violet......
techweb.cmp.com
<<High-power gallium-nitride laser
diodes that emit light in the violet region of the
spectrum have been developed by Nichia
Chemical Industrial Co. Ltd. (Anan, Tokushima).
By operating at a shorter wavelength than blue, the
laser diodes could allow optical disks to store
greater amounts of data, and may find application
in other areas that require blue laser light, such as
flat-panel displays. Nichia researchers described
their work at the recent Spring Meeting of the
Japan Society of Applied Physics and Related
Societies.
Writable power
Researchers at Nichia observed single-mode stable
emission of up to 80-mW output in the diodes.
"DVD applications require 30- to 40-mW power;
thus, our lasers can be used for DVDs," said Shuji
Nakamura, senior researcher at Nichia. "We are
targeting a laser with writable power from the
beginning." Nichia has made the commercialization
of a short-wavelength laser diode a high priority.
"At present, the wavelength at around 400 nm
shows the lowest threshold current," Nakamura
said, "so a [violet] laser with around 400-nm
wavelength will naturally come first."
With plans to sample the parts this year, Nichia
said its laser diodes promise record performance.>> |
