Applications of higher-order phase shifting algorithms for multiple-wavelength metrology

Multiple-wavelength interferometric techniques have been successfully used for large step-height and large deformation measurements. Also it could resolve the step height between smooth and rough surfaces which is not possible with single wavelength interferometry. Temporal phase shifting algorithm,...

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Bibliographic Details
Main Authors: Upputuri, Paul Kumar, Pramanik, Manojit
Other Authors: School of Chemical and Biomedical Engineering
Format: Conference or Workshop Item
Language:English
Published: 2019
Subjects:
Online Access:https://hdl.handle.net/10356/104906
http://hdl.handle.net/10220/49473
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Institution: Nanyang Technological University
Language: English
Description
Summary:Multiple-wavelength interferometric techniques have been successfully used for large step-height and large deformation measurements. Also it could resolve the step height between smooth and rough surfaces which is not possible with single wavelength interferometry. Temporal phase shifting algorithm, which requires a phase shifter such as PZT, has been widely used for accurate phase evolution in interferometry. The phase shifter needs to be calibrated at every wavelength if multiple wavelengths are used for measurement, it is a time consuming process. If phase shifter is not calibrated accurately, it can introduce phase shift errors. In this work, we will discuss various phase shifting algorithms, and their tolerance for phase shift error. And the applications of higher-order phased shifting algorithms will be presented. The study is useful for multiple-wavelength and white light interferometry where more than one wavelength is used for optical phase measurements.