Digital recording and numerical reconstruction of holograms is a new method of laser
metrology: two or more Fresnel holograms, which represent different loading states of the
object, are generated directly on a CCD-target and stored electronically. In contrast to
speckle interferometry, no lens or other imaging device is used. The reconstruction is done
from the digitally stored holograms with numerical methods. For both states, the intensity as
well as the phase of the object wave can be calculated in the reconstruction process. This …

… This method now enables full digital recording and processing of holograms, without any
photographic recording as an intermediate step. Within the scope of this article digital
sampling and numerical hologram reconstruction is called digital holography. Schnars and
Jüptner applied their method to interferometry and demonstrated that digital hologram
reconstruction offers much more possibilities than conventional (optical) processing. The
phases of the stored light waves can be calculated directly from the …