- 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. 2018
- physics a device used in spectroscopy to measure wavelengths by interference effects produced by multiple reflections between parallel half-silvered glass or quartz plates
C20: French étalon a fixed standard of weights and measures, from Old French estalon; see also stallion