an interferometer consisting of two glass plates that reflect approximately half of each ray of light incident upon them and that are separated by a small, fixed distance: used to compare wavelengths and to study atomic spectra.
Origin of etalon
1900–05; < French; Middle French estalon standard, derivative of Old French estal place < Germanic; see stall1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
physics a device used in spectroscopy to measure wavelengths by interference effects produced by multiple reflections between parallel half-silvered glass or quartz plates
Word Origin for etalon
C20: French étalon a fixed standard of weights and measures, from Old French estalon; see also stallion
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012