2. Holography

2.1 Digital holography

As we have already seen, the use of a reference wave makes it possible to use interference to obtain information on the phase of a wave, and therefore on its propagation, and indirectly on depth information. If the interference pattern is recorded on an intensity-sensitive chemical medium, illumination by the original reference wave results in optical reconstruction of the object.

Different holographic set-up configurations exist, for which the position of the source, object and sensor differ (in-line, off-axis, transmission,...