Holographic Versatile Disc What is HVD HVD is

Holographic Versatile Disc

What is HVD? • HVD is a new type of optical storage device • HVD can store from 300 GB in 2008 up to 3. 9 TB • Normal DVD holds 4. 7 GB • Developed by In. Phase Tech & Maxell • Uses 2 lasers to read the same part of the disc by changing the angle of one laser

Holographic? • Leia in Star Wars is a ‘volumetric display’, not a holograph • A hologram is a way to store 3 dimensional images

How does it write the disc? • Two beams are used, the reference beam and the information beam • The reference beam remains unchanged, while the information beam is sent through a spatial light modulator • The beams are recombined, creating an interference pattern of light

Laser Beams? !? • While one beam is used to reflect off the Dichroic mirror layer in the disc, another is used for servo • This servo technology is the same used in CDs & DVDs, using a 650 nm laser to read address pits

How does it read the disc? • When the reference beam is shone onto the disc it returns the pre-recorded interference pattern • The beam is then read by the cmos as a page at about 128 MB/s

Market Info • Technology is slowly becoming easier to make, smaller discs will be available in a few years HVD’s can be mass produced effectively as data can be pre-written when the disc is put together

The End QUESTIONS?