Interferometer

Interferometers are for measuring the interference properties of light waves. One of their purposes is to measure things precisely, for example in the Michelson interferometer.

Interferometer Media

Figure 2. Formation of fringes in a Michelson interferometer
Figure 3. Colored and monochromatic fringes in a Michelson interferometer: (a) White light fringes where the two beams differ in the number of phase inversions; (b) White light fringes where the two beams have experienced the same number of phase inversions; (c) Fringe pattern using monochromatic light (sodium D lines)
Figure 4. Four examples of common-path interferometers
Figure 5. Two wavefront splitting interferometers
Figure 6. Three amplitude-splitting interferometers: Fizeau, Mach–Zehnder, and Fabry Pérot.
Interferometry is used in radio astronomy, with timing offsets of D sin θ
MMX with optical resonators
Fourier transform spectrometer
Figure 11. The VLA interferometer