Concept and Applications of Interference

Concept and Applications of Interference

Interference means redistribution of light intensity due to superposition of two or more light waves. Interference pattern dhus consists of bright and dark fringes. In a typical interferometric setup the light beam is first divided and then reunited with some path difference to form such a pattern the fringe pattern formed the contains information about the source of light and geometry of the film in which interference takes place.

Interference studies are useful in several applications such as reducing or enhancing the reflection of light from glass using films, called antireflection high reflection films testing how flat or a spherical and particular glass surface is the determination of properties like refractive index and Elastic constant of different media. Interferometric techniques also find applications in measurement of the diameters of stars, study of the hyperfine structure of spectral lines, study of transparent or reflecting specimens using interference microscopes and detection of minute variation in the surface finish of videotapes photographic films, computer desks and Ball bearings. Sophisticated techniques like 'computer analysed optical interferometry' have been developed that can detect vibration in the surface texture of the  order of few A (A means angstrom, the unit of wavelength equivalent of 100 millions part of a centimetre).