Course: Learn Laser Interferometry with Finesse

2 Plane waves

2.2 Michelson interferometer

The Michelson is one of the fundamental building blocks of advanced interferometers for gravitational wave detection.

In a Michelson interferometer an incoming laser beam is split into two parts by a central beam splitter. The two beams propagate along two perpendicular arms, each ending with a mirror. The beams are reflected back towards the beam splitter where the they recombine. Any change in the relative length of the interferometer arms results in a change of the light intensity in the interferometer output.