Further information on holographic discs coming forth

November 28, 2005

We were
surprised to read last week that while the Blu-ray camps were busy firing salvos
of press releases at each other, another new storage solution, the holographic
disc was much closer to production than we thought. In that previous story, we
learned that the process, developed at Colorado based InPhase Technologies,
was ready for Maxell to go to manufacture as early as last quarter of 2006.
What is interesting too is, this storage system is a quantum leap from DVD and
even Blu-ray, as this concept can hold 300GB on each layer, with a theoretical
1.6 terabytes per disc for the future! But how does this media work and what
does it look like? Here are some more bits of
information from New Scientist.

The discs, at 13 centimeters across, are a little wider than
conventional DVDs, and slightly thicker. Normal DVDs record data by
measuring microscopic ridges on the surface of a spinning disc. Two
competing successors to the DVD format '“ Blu-ray and HD-DVD '“ use the same
technique but exploit shorter wavelengths of light to cram more
information onto a surface.

Beam-splitter

Holographic memory, by contrast, stores information in a
light-sensitive crystal material using the interference of laser light.
The process involves splitting a single light beam into two and then
passing one through a semi-transparent material. This is a grid that acts
like a filter, changing different parts of the beam to encode bits of
information.

The altered beam and the reference beam are then recombined in the
light-sensitive material and their pattern of interference provides a
record of the encoded information. Information can be recorded and
retrieved so rapidly because many bits of data can be recorded and read in
parallel.

This is different in strategy indeed and quite exciting
to say the least. With the ability to allow a million bits of data to be
written and read in parallel with a single flash of light, the system can
already transfer data at 10 times the speed of DVD. In the article, they
quote InPhase as stating they are expecting to double that data
rate.

Source: New Scientist