etalon

[ eyt-l-on ]

noun

, Optics.

1. 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.

etalon

/ ˈɛtəˌlɒn /

noun

1. 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 History and Origins

Origin of etalon¹

1900–05; < French; Middle French estalon standard, derivative of Old French estal place < Germanic; stall ¹

Word History and Origins

Origin of etalon¹

C20: French étalon a fixed standard of weights and measures, from Old French estalon; see also stallion