Determination of fringe order in white-light interference microscopy.
Combining phase and coherence information for improved precision in white-light interference microscopy requires a robust strategy for dealing with the inconsistencies between these two types of information. We correct for these inconsistencies on every measurement by direct analysis of the difference map between the coherence and the phase profiles. The algorithm adapts to surface texture and noise level and dynamically compensates for optical aberrations, distortions, diffraction, and dispersion that would otherwise lead to incorrect fringe order. The same analysis also provides the absolute height data that are essential to relational measurements between disconnected surfaces.
de Groot
Peter
P
Zygo Corporation, Middlefield, Connecticut 06455, USA. peterd@zygo.com
Colonna de Lega
Xavier
X
Kramer
Jim
J
Turzhitsky
Michael
M