1. Optical holography

1.1 Principle

Optical holography is a technique for recording and reproducing three-dimensional images using coherent light, usually from a laser. It is based on the principle of interference between a reference beam and a beam illuminating the object, thus creating an interference pattern recorded on a photosensitive medium (Figure 1 a). Unlike conventional photography, which only captures light intensity, holography also records the phase of the light, allowing the relief and depth of the object to be faithfully reproduced. When a coherent light beam illuminates the recorded hologram, it recreates the original light wave, giving the illusion of a floating three-dimensional image (Figure...