Keywords:Holography, hologram, photography, wave
This article is about hologram and the basic principle of holography.
Holography is an unusual and unconventional method of producing an image by what is called the wave front reconstruction. In conventional photography the camera consisting of a lens system focuses the light reflected from an illuminated three-dimensional object on a photographic plate (film) where a two dimensional image of the object is formed. Each point of the object is related to a conjugate point in the image. On developing the plate the image can be seen on illumination by an ordinary incoherent light. The drawback of this conventional photography is that the focusing takes place only in a particular plane where all other planes are out of focus. The details of the field nearer and further than the focused plane are thus not available. The photographic plate records the intensity distribution only while the phase distribution at the plane of the photographic plate gets totally lost.
Hence the 3D character if the object cannot be obtained.
Dennis Gabor in 1947 invented a radically new process of image recording in which both amplitude and the phase of a wave are recorded using interferometric principle called holography. It requires highly coherent light.
Modern atomic and nuclear physics—AB GUPTA.