Question

What is fringe in wave optics?

Answer 1

Wave optics, also known as Physic optics, is the study of numerous phenomena like polarization, diffraction, interference, and other occurrences where geometric optics ray approximation is not possible. In the constructive interference bright band is seen and the destructive interference dark band is formed. The fringe in the wave optics is related to these bands.

Complete step by step answer:
Fringe is the alternating light and dark band generated by interference. When two light waves superimpose, they create constructive and destructive interference. The brilliant band results from constructive interference, while the dark band results from destructive interference. The formula $\beta = \dfrac{{\lambda D}}{d}$ is used to calculate the width of the fringe. Here, $\beta$ - Bandwidth, $\lambda$ - Wavelength of the light, $D$ - Distance between the source and the screen and $d$ - Distance between the two slits.

Additional information:
Fringe pattern: Fringe pattern refers to the alternate dark and red bands created on the screen, while fringes refer to the alternate dark and brilliant bands.
Bright Bands: Bright bands are places of maximum intensity that form as a result of constructive interference.
Dark Bands: Dark bands are positions of minimum intensity formed by destructive interference.

Note: We can see that the intensity of a superposition of two waves obtained by amplitude division can be modified by modifying the thickness of the film, the angle of refraction (or angle of incidence), or the wavelength of the light beams. In each of these circumstances, distinct sorts of fringes appear on the screen, which can be categorized into three types.
-Fringes of uniform thickness
-Constant inclination fringes (FOCI)
-Fringes with the same chromatic order (FECO)