Astrophysics (Index)About


(two parallel reflective surfaces separating light according to wavelength)

An etalon is an optical device that uses two reflective surfaces and the distance between them to cancel EMR of some wavelengths and strengthen others. It can use partially-transparent mirrors with an air or vacuum gap between them, or can use two surfaces of one transparent plate. The term is essentially another name for a Fabry-Pérot interferometer (FPI), or can be used to refer to an FPI's inner optics.

Further reading: Interferometer

Referenced by pages:
Fabry-Pérot interferometer (FPI)
Upper Atmosphere Research Satellite (UARS)