Tanner Research is developing state-of-the-art analog circuitry
that implements double-exposure heterodyne
interferometry, a technique that can precisely, yet nondestructively,
measure surface deformation and strain. The key features are
(1) the computations can be made on a local, per-pixel basis,
and (2) integration over time can improve measurement accuracy.
We have already demonstrated the promise of our approach
by designing, fabricating, and testing circuits that compute
the fundamental components of the algorithm.
Because we are developing an integrated circuit that implements
the bulk of the computations, the resulting technology will
be ideal for space-based applications, where power, size,
and mass are at a premium. In fact, the initial application
we are targeting is space-based optical
metrology. Another advantage is that an analog chip can
be readily scaled to meet the needs of future processing requirements
for large pixel counts (necessary for high spatial resolution)
and high frame rates (necessary for closed-loop control or
measurement of quickly changing deformation). Such scalability,
combined with the technology's affordability, will open up
revolutionary terrestrial capabilities as well.
This research has been sponsored by the U.S. Air Force under