Expanding and focusing beam of light makes parallel computer

Image of multiple beams of light entering a device and exiting as a single beam.

Enlarge / If everything’s
set up properly, you know you have a solution when the input light
results in a single point of light as the output. (credit:
Robert Horn/Argonne National Laboratory
)

When it comes to computation, the modern approach seems to
involve an enormous bucket of bits, vigorous shaking, and not a lot
of explanation of how it all works. If you ever wondered how Excel
became such an abomination, now you know.

We don’t seem to have a problem creating and filling enormous
buckets of bits, but shaking them up is energy-intensive and slow.
Modern processors, as good as they are, simply don’t cope well
with some problems. A light-based, highly parallel
processor
may just be the (rather bulky) co-processor that
we’ve been looking for to handle these tasks.

Solutions are downhill

One way to compute a solution to a problem is called annealing.
I’ve
written a lot
about annealing in the context of
quantum computing
, but annealing works for classical computers
as well. The essential idea is that a
problem is recast
so that the solution is the lowest energy
state of an energy landscape. The landscape determines how strongly
the value of one bit affects the value of the surrounding bits.

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Source: FS – All – Science – News
Expanding and focusing beam of light makes parallel computer