Origin of etalonFrench étalon, a standard of weights and measures from Old French estalon: see stallion
An example of etalon is the equipment used to stabilize the wavelength of a laser.
Origin of etalonFrench étalon standard (of weight or a unit of measurement), reference point, etalon (in reference to the fixed widths between the two surfaces in the first such interferometers) from Old French estalon standard, of Germanic origin Middle Dutch stael model, sample
etalon - Computer Definition
A spectroscopic instrument used to measure and control optical wavelengths. Also known as an interferometer, an etalon comprises two parallel reflecting plane surfaces. Etalons are widely used in lasers. See also Fabry-Perot laser.