Even though we have yet to see the latest rumored 100GB and 200GB prototype Blu-ray discs, TDK is looking beyond already.
TDK has always pushed the limits. Earlier, we heard that they are planning 960GB laptop drives and 3.2TB desktop drives. Now, they are ready to demo 320GB ten-layer platters at CEATEC 2009, based on Blu-Ray technology.
Key in stacking so many layers is achieved by improving the transmittance of the outermost layer. High Density BluRay doesn’t need a more powerful laser to get through, but rather demands a better topmost surface capable of transmitting approx 99% of the light through it.
With DVDs, we haven’t seen this going above dual-layer because of the higher wavelength of the Red-laser, which has been overcome with Blue Laser that powers Blu-Ray technology.
Imagine a 10 layer disc, still possible to write and read data on and from the disc by using a blue-violet semiconductor laser with an oscillation wavelength of 405nm and an objective lens with a numerical aperture (NA) of 0.85.
On the outerside, there’s a cover layer, a hard coat layer which protects BluRay discs from scratches, recording layers and a Si-Cu alloy layer reside inside.
The company has tested the disc and has found it to be reliable enough for commercial use;that’s why we will see it at CEATEC trade show in Japan next week. And then we will see World’s largest Blu-Ray DVD disc, LIVE!