(1) (
Hosted
Virtual
Desktop) See
virtual desktop.
(2) (
High
Voltage
Differential) See
SCSI and
differential signaling.
(3) (
Holographic
Versatile
Disc) A high-capacity optical disc from the HVD Forum that combines single beam holographic storage and DVD technologies to provide cartridge capacities reaching 4TB and beyond. Formed in 2005 as the HVD Alliance, the first standards were released in 2007 for 100GB read-only and 200GB recordable formats. To date, there are no commercial products.
Single Beam Holography
Throughout the history of holographic storage research, two separate laser beams have been used to write the holograms at the intersecting point. Using Optware's Collinear Holography, HVD combines the two lasers into one lens, which reduces the size and cost of the mechanism. See
holographic storage.
Layers in an HVD Disc
HVD uses the conventional CD/DVD pit layer for addressing the disc, on top of which is the holographic recording layer. A red laser reads the addresses, while a green or blue laser reads and writes the holograms.