Holography

Holography is an imaging technique that records a wavefront as an interference pattern and later reconstructs it, and it is best known as a way of producing three-dimensional images. A hologram is made by overlaying a second wavefront, the reference beam, on the wavefront of interest and capturing the interference pattern on a physical medium; when the recording is lit again it diffracts light to recreate the original light field, with the depth, parallax and perspective of the original scene. Optical holography needs laser light to record, though cheap mass-produced laser diodes now make it accessible to researchers, artists and hobbyists. Beyond images it is used for data storage, microscopy and interferometry. Dennis Gabor invented it in 1948 while seeking better image resolution in electron microscopes at the British Thomson-Houston company.