What phenomenon occurs when light waves meet and create interference patterns?

The phenomenon that occurs when light waves meet and create interference patterns is known as interference. This process happens when two or more coherent light waves overlap in space, combining their amplitudes, which results in regions of constructive interference (where the waves amplify each other) and destructive interference (where the waves cancel each other out). This can create a variety of patterns, such as those seen in thin films, such as soap bubbles or oil slicks, where you observe colorful variations due to the different thicknesses of the films influencing how the light waves combine.

In the context of optics, understanding interference is crucial because it informs various applications, including the design of optical devices and analysis of material properties based on how they interact with light. Other phenomena like diffraction, refraction, and reflection describe different behaviors of light but do not specifically involve the overlapping of light waves leading to patterns. Diffraction relates to the bending of light around obstacles; refraction refers to the bending of light as it passes from one medium to another; and reflection is the bouncing back of light from surfaces. Each of these plays a significant role in optics, but none results in the interference patterns that are characteristic of the interference phenomenon.