Holography is a method of visually reproducing objects as three-dimensional images. Unlike traditional photography, an object captured in a holographic image can change perspective based on the location of a viewer. There are several applications of holography including art, information storage, and security.
The word "holography" comes from the Greek term for "whole drawing." The holographic process was developed by physicist Dennis Gabor in 1947. It was not until 1962, however, that three-dimensional viewable holograms became practical to create. This depended on expensive equipment and expert knowledge in the early years of its development. The prevalence of cheap lasers and other supplies in the early 2000s has since made holography available to hobbyists on a budget.
One of the most common applications of holography is art. Three-dimensional holograms allow artists to capture interesting objects and scenes which can be viewed from many angles. The famous surrealist artist Salvador Dali was one of the first to employ this as art in 1972. A wide variety of holographic artwork can be explored at a number of museums and other locations throughout the world.
Information storage is another one of the applications of holography. Holograms are able to hold a vast amount of data, which does not necessarily have to be in a visible image format. A single image can contain a variety information that may be accessed by reflecting light from different angles. Traditional optical storage methods, such as compact discs, can be accessed from only one angle. Several companies are researching the use of holograms as high-capacity data storage devices for entertainment and computing purposes.
This type of image reproduction can also be used in security applications. Complex holograms are much more difficult to reproduce compared to static images. For this reason, holograms are often placed on valuable items to reduce the chances of forgery. Common security applications of holography include labels on credit cards and images embedded in government currency. Important documents such as passports and identification cards also often use them to discourage illegal reproduction.
Research into new applications of holography is ongoing. Many scientists believe that holograms can be used to create realistic moving projections of people and objects. In the future, data that previously required 100 DVD disks can be contained in a single flat hologram. The development of optical computing may lead to even more uses, and dramatically increase the processing speed and storage capacity of computers.