Light interference occurs when two or more light waves interact with one another, resulting in a combination of their amplitudes. The resulting wave may increase or decrease in strength.
- A simple form of interference takes place when two plane waves of the same frequency meet at an angle and combine.
- Light interference is often observed as interference patterns, such as seen in supernumerary rainbows.
- Interference patterns are produced when the energy of waves combines constructively or destructively. For example, waves on a pond can create interference patterns.
- Constructive interference occurs when the crest of one wave meets the crest of another wave of the same frequency at the same point. The resulting wave is the sum of the amplitudes of the original waves.
- Destructive interference occurs when the trough of one wave meets the crest of another wave. The resulting wave is the difference between the amplitudes of the original waves.