Another big step forward in GE’s holographic data storage program

[ Thanks to Hans
Bezemer for this link. ]

“You may be asking, “what is threshold recording
behavior?” Well, it is a fancy way of saying that we are looking to
develop a material that records data in a way that is similar to
how other optical disc technologies (CD, DVD, or BD) record data.
That is, when the optical drive is reading a disc, the laser power
is turned down to relatively low levels. To record data the laser
power inside the drive will be turned up to high power. This high
power enables the laser to create changes in the recording layer of
the disc. For example, a laser power of 1 mW might be used to read
a CD or DVD, which is less than most laser pointers generate, but a
laser power of 10 to 50 mW might be used to record. So to put it
simply, threshold behavior refers to the low-power readout and
high-power recording process. However, this is where the
similarities between the previous generations of optical storage
and holographic storage end. In CDs, DVDs, or BDs, the recording is
done by making marks (or changes) in a thin recording layer in the
disc. These marks are typically made by changing the reflectivity
of the recording layer – think of it as making microscopic damage
spots in a mirror.”

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