Thin Film Interference

Thin film interference occurs when light waves reflect off the top and bottom surfaces of a very thin layer of material, like soap bubbles or oil on water. These reflected waves can combine, either amplifying or canceling each other, depending on their phase difference. This interaction creates colorful patterns or iridescence, which change with viewing angle and thickness of the film. The phenomenon is a result of the wave nature of light and the specific conditions under which constructive (bright) or destructive (dark) interference occurs, producing the visually striking effects seen in many everyday thin films.