P3D Re Holaroid Process Update

[Peter Homer <P.J.Homer@xxxxxxxxxxxxx>]

Actualy this does not sound all that new I have a book on holography which
describes similar sytems and they are of very specialised interest. The
term interferometry is a clue. The idea I believe is to holograph an object
and then leaving the set up exactly as it is develop the hologram quickly
so that it can then be put back into the set up. With laser illumination a
second hologram is produced in effect overlapping the recorded one. The
object is then put under some stress so the slight deformation causes the
second hologram to be out of register with the first producing a Moir'e
pattern showing the stress distribution in the object. There is an older
technique which used models of the the object in transparent photoelastic
or a reflective subject coated in photoelastic and polarised light. Apart
from the developing it is as problematic as normal holography.    P.J.Homer



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