In a double-slit experiment, the bright fringe refers to a region on the observation screen where constructive interference occurs, resulting in a bright spot or band of light. It is one of the characteristic patterns that emerges when coherent light or particles pass through two closely spaced slits.
In this experiment, a beam of light or a stream of particles, such as electrons or photons, is directed toward a barrier that contains two parallel slits. The incident light or particles pass through both slits and then spread out as they propagate beyond the slits.
When the light or particles reach an observation screen positioned some distance away from the slits, an interference pattern is observed. This pattern consists of alternating dark and bright fringes. The bright fringes are areas of constructive interference, where the crests of the waves from the two slits coincide, resulting in an increased amplitude and intensity of light or particle accumulation.
The spacing between the bright fringes is determined by the wavelength of the incident light or particles and the distance between the slits. The closer the slits are together or the longer the wavelength, the wider the spacing between the bright fringes.
The presence of bright fringes in the double-slit experiment is a characteristic feature of wave interference and provides evidence for the wave-like nature of light and particles.