Phase Retrieval Algorithm for Form Testing Metrology in Production Environment

• Main Authors: Stephan Stuerwald, Robert Schmitt
• Format: Article
• Language: English
• Published: International Institute of Informatics and Cybernetics 2010-08-01
• Series: Journal of Systemics, Cybernetics and Informatics
• Subjects: Algorithm; Surface Inspection; Quality Assurance; Form Measurement; Interferometry
• Online Access: http://www.iiisci.org/Journal/CV$/sci/pdfs/GO774PY.pdf

Form testing interferometry permits a fast, non-tactile and full- field quantitative phase imaging of components in ultra precise manufacturing. To reduce the influence of vibrations under manufacturing conditions, it is most common to use the FT- based spatial carrier phase measurement technique (SCPM) which requires only a single interferogram recording. The utilization of a generalized, relatively new spatial phase-shifting method operating in the position space opens up prospects for reduced phase noise and less reconstruction errors of the calculated phase-map under production conditions. Therefore this phase-shifting technique is investigated for applicability in machine integrated interferometric form testing of optical lenses. A characterization of the algorithm and a comparison with the commonly used FT-based algorithm is performed. As a reference, measurements are carried out with a coordinate measuring machine with nanometre accuracy.