What is dark fringe in physics?

In physics, a dark fringe refers to a region of minimum or zero intensity in an interference pattern, such as in the double-slit experiment. Dark fringes occur when the crests of one wave align with the troughs of another wave, causing destructive interference and resulting in a decrease or cancellation of the overall intensity of the light at that point. Dark fringes are characterized by a lack of light or a decrease in brightness compared to the surrounding areas of the interference pattern.

In interference, a dark fringe is a minimum-intensity region where the interfering waves are exactly out of phase and cancel each other out. This occurs when the path length difference between the two waves is an odd multiple of half a wavelength, or an odd number of half-wavelengths. Dark fringes are typically observed in double-slit experiments, where they appear as dark bands parallel to the slits.