Single-shot dispersive interferometry for inline surface inspection

Dawei Tang, Jian Wang, Tianqi Gu, Hussam Muhamedsalih, Tong Guo, Jane Jiang

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


The dispersive interferometry provides an instantaneous surface measurement in a single camera frame, making it resistant to environmental disturbances and ideal for in-process surface metrology. It also benefits from the extended measurement ranges in both depth and lateral directions by incorporating hyperspectral imaging technology and cylindrical beam illumination, respectively. This paper reports on an in-house developed cylindrical lens-based dispersive interferometer for high-accuracy surface inspection, particularly for structured surfaces. The obtained spectral interferogram is analyzed using the fringe order algorithm, in which the phase slope method is used to calculate the initial height to resolve the fringe order ambiguity and eventually an improved height value can be obtained using the exacted phase of a single wavelength. Experiments demonstrate that the measurement noise of the developed interferometry system is less than 1 nm within the measurement range. A brass step sample made by a diamond turning machine was measured and the experimental results closely align with those given by the commercial white light interferometer -Talysurf CCI 3000.

Original languageEnglish
Title of host publicationOptical Metrology and Inspection for Industrial Applications X
EditorsSen Han, Gerd Ehret, Benyong Chen
Number of pages7
ISBN (Electronic)9781510667884
ISBN (Print)9781510667877
Publication statusPublished - 27 Nov 2023
EventOptical Metrology and Inspection for Industrial Applications X 2023 - Beijing, China
Duration: 14 Oct 202317 Oct 2023

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceOptical Metrology and Inspection for Industrial Applications X 2023

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