Michelson Interferometer
An optical instrument that splits a beam of light into two perpendicular paths and recombines them to create high-precision interference fringes.
Governing formula
2 d = m λ
SI unit
m
In depth
Shifting one mirror by distance $d = λ/2$ causes one complete fringe shift. Used for sub-nanometer distance and wavelength measurements.
Examples in the real world
LIGO detector using giant 4-kilometer Michelson interferometers to detect gravitational waves measuring $10^{-19}$ meters.