holographics

Holographics is the science and technology surrounding holography, the practice of recording and reconstructing the light field from an object to produce a three-dimensional image. A hologram captures both the intensity and the phase of light by exposing a photosensitive medium to the interference pattern formed between a reference beam and light reflected from or emitted by the object. When later illuminated with a beam similar to the reference, the hologram diffracts light to recreate a three-dimensional wavefront, giving the viewer depth and parallax.

The field began with the theoretical work of Dennis Gabor in 1948, aimed at improving electron microscopy. Practical holography emerged after lasers were developed in the 1960s, with Emmett Leith and Juris Upatnieks producing early successful holograms. Since then, holographics has evolved through advances in recording media, such as volume holograms and photopolymers, and the rise of digital and computer-generated holography, which enable design and processing of holograms without physical objects.

Techniques in holographics include transmission holograms, viewed with light passing through the medium, and reflection holograms, viewed with light reflecting off the hologram. Volume holograms store information throughout the material thickness, offering high storage density. Computer-generated holograms are designed computationally and produced by printers or spatial light modulators, supporting holographic displays and optical components. Digital holography uses electronic sensors to capture and reconstruct holograms.

Applications of holographics span data storage research, security features on documents and products, art and media, three-dimensional displays, medical imaging and diagnostics, non-destructive testing, and metrology. The field continues to grow with new materials, digital processing, and advancements in display and imaging technologies.