Holography

Basic Concepts

Holography is a technique that uses the interference and diffraction of light to record and display three-dimensional images. Hologram is a photographic technique that records the light scattered from an object, and uses that information to display a 3D image of the original object

Recording of Hologram

The process of recording a hologram involves shining a laser beam onto an object, which reflects a portion of the beam onto a recording medium, such as holographic film or a holographic plate. A second beam, known as the reference beam, is directed onto the recording medium at a different angle. The interference between the two beams creates a pattern on the recording medium that is a record of the object's wavefront.

Recording of hologram

Reconstruction of Holograms

To reconstruct a hologram, a laser beam is directed onto the holographic plate. The light scattered by the hologram interferes with the reference beam to create a three-dimensional image of the original object.

Reconstruction of image

Comparison with Photography

Holography Photography
Records three dimensional image of object Records two dimensional image of object
Records the phase and amplitude of light waves Records only the amplitude of light waves
Holograph is due to interference between object wave and reference wave Photograph plate records the intensity variation of light reflected from object
If broken into pieces, the full information of object can be degenerated from each piece If broken into pieces, each piece will provide only the partial information of the object
Requires laser light source for reconstruction Does not require special light source for viewing
Can store multiple views in a single hologram Stores only a single view per photograph

Applications of Holography

Holography has a wide range of applications in various fields such as science, technology, medicine, and art. Some of the most notable applications are: