Computer Generated Holograms (CGHs) is an emerging technology made possible by increasingly powerful computers that avoid the interferometric recording step in conventional holograms. In order to find the CGH as a mathematical function, the desired pattern is prepared and corresponding optical element(s) are calculated by a digital computer. Reconstruction is fulfilled with a device realized as a diffractive optical element (DOE) with surface relief profile or a phase-only spatial light modulator (SLM) as a few examples.
Advantages
- Images of non-existent objects can be produced.
- The images do not rely on the availability of specialized holographic recording materials.
- Production steps are straightforward and free of experimental elaboration and errors.
- CGHs offer unprecedented wavefront control by making it easy to store, manipulate, transmit, and replicate holographic data thus this technology.
- Enables a wide range of display types, including 2D, stereoscopic, auto-stereoscopic, volumetric, and true 3D imaging.
Applications fields other than generic display systems include aspherical surface testing, optical interconnections, beam shaping, head-up displays, and security-based optical image encryption systems.