Editing Wave interference (section)

==== Optical arrangements ====
To generate interference fringes, light from the source has to be divided into two waves which then have to be re-combined. Traditionally, interferometers have been classified as either amplitude-division or wavefront-division systems.

In an amplitude-division system, a [[beam splitter]] is used to divide the light into two beams travelling in different directions, which are then superimposed to produce the interference pattern. The [[Michelson interferometer]] and the [[Mach–Zehnder interferometer]] are examples of amplitude-division systems.

In wavefront-division systems, the wave is divided in space—examples are [[Young's double slit experiment|Young's double slit interferometer]] and [[Lloyd's mirror]].

Interference can also be seen in everyday phenomena such as [[iridescence]] and [[structural coloration]].  For example, the colours seen in a soap bubble arise from interference of light reflecting off the front and back surfaces of the thin soap film.  Depending on the thickness of the film, different colours interfere constructively and destructively.

<gallery mode="packed" caption="Iridiscence caused by thin-film interference">
File:Samsung Galaxy A50 back 2.jpg|Smartphone with iridescent back panel
File:Dieselrainbow.jpg|An oil spill
File:Soap bubble sky.jpg|White light interference in a soap bubble.
</gallery>