What is Michelson interferometer?
{{Orphan|date=May 2009}} The '''Michelson interferometer''' is the [[tool]] used for optical [[interferometry]]. == Background == It was invented by [[Albert Abraham Michelson]], famous for proving that [[luminiferous aether]] did not exist in the [[Michelson-Morley experiment]]. == How it works == [[File:Michelson Interferometer.jpg|thumb|300px]] There are two [[Mirror|mirrors]] in the interferometer, one fixed and the other movable through a [[micrometer]]. There is also a [[beam splitter]] that separates the [[laser]] or light beam and a screen that shows the [[interference]] pattern. A wide [[laser]] or light beam is first shot at the beam splitter. [[Reflection]] takes place as the beam hits the beam splitter, part of it reflects towards mirror 1 while the rest towards mirror 2. The two beams again reflect off mirror 1 and 2 and travel back to the beam splitter. The two beams that goes through the beam splitter will combine and form an [[interference pattern]] at the screen. The interference pattern will appear as bands and each band represents 2 path length difference or 1 [[wavelength]]. That is because the [[Crest (physics)|crest]] of wave 1 has caught up with the crest of wave 2 (or the other way around), causing a [[constructive interference]]. If given the change in distance of the movable mirror and number of bands on the screen, we can easily calculate the [[wavelength]] of the light source. [[Category:Measuring tools]] [[Category:Optics]] [[Category:Astrophysics]]