How does diffraction occur at a double slit?

Diffraction occurs at a double slit due to the interference of light waves.

When light waves pass through a double slit, they diffract and interfere with each other. This interference pattern creates a series of bright and dark fringes on a screen placed behind the slits. The bright fringes occur when the waves from each slit are in phase, meaning their peaks and troughs line up, creating a constructive interference. The dark fringes occur when the waves are out of phase, creating destructive interference.

The spacing between the fringes is determined by the distance between the slits and the wavelength of the light. This is known as the diffraction grating equation, which is given by d sinθ = mλ, where d is the distance between the slits, θ is the angle between the screen and the incident light, m is the order of the fringe, and λ is the wavelength of the light.

The double slit experiment is often used to demonstrate the wave nature of light and the principles of diffraction and interference. It has also been used to study the properties of other waves, such as electrons and atoms. The experiment has played a significant role in the development of quantum mechanics and our understanding of the fundamental nature of matter and energy.