Editing Beam splitter (section)

== Use in experiments ==
Beam splitters have been used in both [[thought experiment]]s and [[Experimental physics|real-world experiments]] in the area of [[quantum mechanics|quantum theory]] and [[relativity theory]] and other fields of [[physics]].  These include:
* The [[Fizeau experiment]] of 1851 to measure the speeds of light in water
* The [[Michelson–Morley experiment]] of 1887 to measure the effect of the (hypothetical) [[luminiferous aether]] on the speed of light
* The [[Hammar experiment]] of 1935 to refute [[Dayton Miller]]'s claim of a positive result from repetitions of the Michelson-Morley experiment
* The [[Kennedy–Thorndike experiment]] of 1932 to test the independence of the speed of light and the velocity of the measuring apparatus
* [[Bell test experiments]] (from ca. 1972) to demonstrate consequences of [[quantum entanglement]] and exclude [[local hidden-variable theory|local hidden-variable theories]]
* [[Wheeler's delayed choice experiment]] of 1978, 1984 etc., to test what makes a photon behave as a wave or a particle and when it happens
* The [[Free-orbit experiment with laser interferometry X-rays|FELIX]] experiment (proposed in 2000) to test the [[Penrose interpretation]] that [[quantum superposition]] depends on [[spacetime curvature]]
* The [[Mach–Zehnder interferometer]], used in various experiments, including the [[Elitzur–Vaidman bomb tester]] involving [[interaction-free measurement]]; and in others in the area of [[quantum computation]]