Open AccessFourier-transform spectral interferometry for in situ group delay dispersion monitoring of thin film coating processes
Author(s) -
S. Schlichting,
Thomas Willemsen,
Henrik Ehlers,
Uwe Morgner,
Detlev Ristau
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.022516
Subject(s) - optics , michelson interferometer , interferometry , dispersion (optics) , coating , group delay dispersion , materials science , optical coating , group delay and phase delay , interference (communication) , fourier transform , spectrometer , phase (matter) , white light interferometry , stack (abstract data type) , physics , optical fiber , telecommunications , computer science , fiber optic sensor , nanotechnology , channel (broadcasting) , bandwidth (computing) , quantum mechanics , dispersion shifted fiber , programming language
A fast Fourier-based measurement system to determine phase, group delay, and group delay dispersion during optical coating processes is proposed. The in situ method is based on a Michelson interferometer with a broad band light source and a very fast spectrometer. To our knowledge, group delay dispersion measurements directly on the moving substrates during a deposition process for complex interference coatings have been demonstrated for the first time. Especially for the very precise production of chirped mirrors it is advantageous to get information about the phase properties of the grown layer stack to react on errors and retrieve more information about the coating process.