Sanyo record raises blue diode power stakes
Sanyo has sent a warning message to Blu-ray recorder producers by developing the world s highest-output 405 nm blue-violet laser diode.
The pulsed-operation 450 mW GaN laser unveiled on October 3 could allow the Japanese technology corporation to make a big impact on the Blu-ray recorder market.
Uniquely, Blu-ray technology in Japan is currently driven by strong demand for recording devices, where higher-power diodes are crucial.
Sharp now dominates this market, surging from a 10 percent share in December 2007 to over 34 percent in August 2008, according to research firm BCN, Inc, as reported on Nikkei.net.
This lead, which saw Sharp overtake its main rivals Sony and Panasonic, appears to stem from a diode that it announced in April. At 250 mW the GaN diode is the highest-power offering in the market.
The 250 mW diode enables Blu-ray recording at 4x standard recording speeds, and Sharp aims to have 6x recorders on the market in 2009.
In establishing its market lead, the company has focussed strongly on developing its own GaN technology. Sony and Panasonic, by contrast, rely to some extent on buying lasers and cross-licensing technology to manufacture them in-house from Nichia.
When used with four-layer Blu-ray discs the 450 mW device enables 12x recording, positioning Sanyo to emulate Sharp s recent ascent.
Under continuous operation, the diode s record power output falls to 200 mW. The device s current threshold is 50 mA, and at 200 mW operation the operating current is 200 mA.
The boost in power is attributed in part by Sanyo to using simulations to help ensure a stable beam position in the laser's optical waveguide. High-precision dry etching helps ensure that the simulated design is actually produced, yielding a more stable optical output.
It also says that it has grown high crystal quality optical cladding layers, reducing the extent of optical loss. The edges of the laser have also been coated in a protective membrane that boosts long-term reliability.
