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Calibrating the sag due to gravity of horizontal interferometer reference flats

Published

Author(s)

Ulf Griesmann, Jan Burke

Abstract

We describe a method for measuring the deflection due to gravity (sag) of horizontally mounted reference flats of phase shifting interferometers. The planarity of a test flat can be measured sag- free while supporting it iso-statically on a suitable visco-elastic polymer foam. A sag map is obtained when the sag-free flatness error is subtracted from the flatness error of the same flat held at its edge.
Proceedings Title
Interferometry XVI: Techniques and Analysis
Volume
8493
Conference Dates
August 13-15, 2012
Conference Location
Monterey, CA
Conference Title
SPIE Optics & Photonics 2012

Keywords

Optical interferometry, Reference flat calibration, Sag

Citation

Griesmann, U. and Burke, J. (2012), Calibrating the sag due to gravity of horizontal interferometer reference flats, Interferometry XVI: Techniques and Analysis, Monterey, CA, [online], https://doi.org/10.1117/12.929968 (Accessed April 17, 2024)
Created September 13, 2012, Updated June 23, 2020