PORTLAND, Ore. GE Global Research reports that is has succeeded in writing patterns on holographic disks that brighten their reflectivity by up to 200 times, enabling next-generation holographic disks that could store up to 500 Gbytes, or about 10 times the storage capability of Blu-ray video disks.
Optical disk drives with vastly more data storage than current storage media promise to harness the third dimension to write holographic patterns. Last year, GE said it had successfully used 405-nm wavelength blue lasers to enable its next-generation holographic disks to be backward compatible with existing high-density Blu-ray disks. However, the patterns written were too faint to be recorded in the sub-micron domains necessary to exceed Blu-Ray densities. T
"We are creating chemical changes in microscopic patterns that will generate higher reflectivity when read by a low-power laser," said Brian Lawrence, manager of GE's Integrated Polymer Systems Lab (Niskayuna, N.Y.). "We created a material in which the refractive index can be changed when exposed to high laser power."
Standard CDs and DVDs use low-power lasers to read disks (about 1 milliwatt), then switch to high-power mode (about 50 milliwatts) for recording, which essentially introduces microscopic damage that reduces the reflectivity of the disk. GEs holographic method uses a media which increases its reflectivity when written, a more complicated process that yields much higher densities than are possible using traditional threshold recording behaviors. The result is the creation of as many 50 virtual layers on a disk.
GE estimates that its 500-Gbyte disk drives will be available by late 2011, using media that costs about 10 cents/gigabyte compared to 50 cents/gigabyte for current Blu-ray media.