Interferenssivärejä

Interferenssivärejä, or interference colors in English, are colors seen when light waves interfere with each other. This phenomenon occurs when light reflects off thin films or layered surfaces. The thickness of the film and the angle of observation are crucial factors determining the resulting colors.

When light strikes a thin film, such as a soap bubble or an oil slick on water, some of it reflects off the top surface, while some enters the film, reflects off the bottom surface, and then exits. These two reflected light waves are now slightly out of phase. Depending on the film's thickness, certain wavelengths of light will constructively interfere, meaning their peaks and troughs align, making those colors appear brighter. Other wavelengths will destructively interfere, where their peaks align with troughs, canceling each other out and making those colors less visible.

The colors we perceive are the result of this selective reinforcement and cancellation of different wavelengths of light. As the thickness of the film varies across its surface, or as the observer changes their viewing angle, the interference patterns change, leading to the vibrant, swirling colors characteristic of interference colors. Common examples include the iridescent sheen on a beetle's wing, the colors seen in gemstones like opals, and the rainbow-like patterns on a CD or DVD.