System for observing interference phenomenon :

In the previous section, we have discussed about the interference phenomenon arising due to division of wave fronts and division of amplitudes. Various systems based on these principles have been designed and are used to observe these phenomenon. These systems find several applications in science and engineering such as measurement of wavelength of a light source, the wavelength difference between two closely separated waves, the optical flatness of surfaces, thickness of the film, refractive index of material etc. We shall be discussing some of these systems and their applications in the following sections. The major systems for observing interference phenomenon are as follows.

1. Fresnel Biprism
2. Newton's ring
3. Michelson interferometer
4. Fabri-Perot interferometer.