A hologram is a technique that records and reproduces a three-dimensional light field by using interference and diffraction of coherent light, such as a laser beam. A hologram can create an image that has depth, parallax and other properties of the original scene, without the need for a lens. A hologram is made by splitting a laser beam into two beams: one that illuminates the object and one that serves as a reference. The interference pattern between the two beams is recorded on a photographic film or other medium, and can be reconstructed by illuminating it with the reference beam again.
