Open AccessEffect of retrace error on stitching coherent scanning interferometry measurements of freeform optics
Author(s) -
Hossein Shahinian,
Clark Hovis,
C. J. Evans
Publication year - 2021
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.433435
Subject(s) - image stitching , optics , interferometry , fizeau interferometer , coherence (philosophical gambling strategy) , measurement uncertainty , physics , metrology , aperture (computer memory) , observational error , astronomical interferometer , mathematics , acoustics , statistics , quantum mechanics
We report on the effect of retrace error during measurement of freeform optics using a commercial coherence scanning interferometer (CSI), and its in-built stitching capabilities. It is shown that measuring segments of freeform optics under non-null conditions, results in artifacts on the measured zone, similar to the Seidel aberrations. An experimental approach is used to quantify the induced aberrations based on the local slopes of the surface. Simulation of surfaces containing different order aberrations is shown to have a significant effect on the measurement data. A correction method is proposed that uses experimental measurements to determine the required correction based on local slope and position in the aperture. These corrections reduce the measurement difference from a comparison measurement using a Fizeau interferometer.