The Michelson interferometer splits a beam of light into two paths at right angles, sends each along its own arm to a mirror, and recombines them, so that any difference in the distance the light travelled shows up as a shift in the interference pattern. Albert A. Michelson built the device in 1881, and used it with Edward Morley in 1887 in an attempt to detect Earth's motion through a supposed luminiferous ether; the experiment's null result helped clear the way for Einstein's special theory of relativity.
Facts
Invented Year MeasuresInterference patterns arising from the path-length difference between two recombined light beams, used to measure distance, strain and wavelength with extreme precision. 1 Operating PrincipleA beam splitter divides a light source into two perpendicular arms, each reflected back by a mirror; the two beams recombine at the beam splitter and interfere, and the resulting pattern depends on the path-length difference between the arms. 1 ResolutionPrecise to the scale of a light wavelength; coherent laser sources can resolve path differences of millions to billions of wavelengths. 1 Operating RangeNot a single fixed range; scale depends on the light source's coherence length, from micrometers for ordinary white light up to kilometer-scale arms in the largest gravitational-wave detectors, such as LIGO's 4-kilometer arms. 1 Classification
Instrument Class Connections
Invented By
Built the interferometer in 1881 to detect minute differences in the speed of light travelling in perpendicular directions, then used it again with Edward Morley in 1887 in the famous null-result experiment.
Source Michelson Interferometer (Britannica)
Named After
Source Michelson Interferometer (Wikipedia)
Used In
Source Michelson Interferometer (Britannica)
Source Michelson Interferometer (Britannica)
Sources
1. Michelson Interferometer (Wikipedia)
Wikipedialead section
The Michelson interferometer is a common configuration for optical interferometry and was invented by the American physicist Albert Abraham Michelson in 1887.
Configuration section
reflected back toward the beamsplitter which then combines their amplitudes using the superposition principle
Sources section
differential pathlengths of millions or even billions of wavelengths
Applications section
two Michelson interferometers, each with 4 km arms
Lede, instrument class
The Michelson interferometer splits a beam of light into two paths at right angles, sends each along its own arm to a mirror, and recombines them, so that any difference in the distance the light travelled shows up as a shift in the interference pattern.
- Named After: Albert A. Michelson
View the Source 2. Michelson Interferometer (Britannica)
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