Yes, interference does occur in coherent light that passes through two slits. This phenomenon is known as Young's double-slit interference and is a fundamental demonstration of the wave nature of light.
When coherent light, such as laser light, passes through two closely spaced slits, it diffracts and creates a pattern of alternating bright and dark fringes on a screen placed behind the slits. This pattern is the result of constructive and destructive interference between the light waves that pass through the slits.
Each slit acts as a source of secondary waves, and these waves interfere with each other. Where the peaks (or crests) of the waves coincide, constructive interference occurs, resulting in bright fringes or regions of increased intensity. Conversely, where the peaks of one wave align with the troughs of another wave, destructive interference takes place, resulting in dark fringes or regions of decreased intensity.
The interference pattern formed by the double-slit setup is characteristic of wave interference and cannot be explained by particle behavior alone. It is a fundamental phenomenon that supports the wave-particle duality of light.