Principles of Display Holography

Display holography describes a diffraction- and interference-based coherent imaging technique in which a three-dimensional object or scene is represented by a flat, two-dimensional screen—the hologram. This screen has a sophisticated transparency that encodes both amplitude and phase values. When properly illuminated, the three-dimensional object is reconstructed by the hologram. Using this basic principle, both static and dynamic holographic imaging can be realized. This chapter outlines the various holographic methods that have been developed over the years for three-dimensional holographic imaging of objects. A distinction is made between holograms that are recorded in a holographic material (analog film) and those that are displayed by an electronic device (digital device, e.g., spatial light modulator). Film holograms allow static reconstructions (still images), while electronic holographic displays aim to show time-varying reconstructions in real time (holographic movies). Finally, some of the capturing methods used to create 3D content are briefly described.