Optical measurement of surface topographies with transparent coatings

Feng, Xiaobing; Senin, Nicola; Su, Rong; Ramasamy, Suresh; Leach, Richard

Abstract

Manufacturers nowadays have access to state-of-the-art areal surface topography measurement instruments that allow investigation of surface topography at unprecedented levels of detail and over a wide range of scales. However, high value-added products have demanding requirements, pushing measurement technologies to their limits. Therefore, a deeper insight and more comprehensive understanding of performance and behaviour of current areal surface topography measurement solutions is often needed. In this work, we investigate and compare the results when measuring the same surface with different, state-of-the-art areal surface topography measurement solutions involving the principal optical technologies, notably focus variation microscopy, coherence scanning interferometry, imaging confocal microscopy and point autofocus instrument, operated using different set-ups. The test case is a highly engineered surface obtained through a sequence of mechanical and chemical surface modification processes. The surface has complex topographic formations at micrometre and sub-micrometre scales, and is characterised by the presence of a thin transparent layer, notoriously challenging for optical measurement. The topographies reconstructed from measurement are compared both in terms of visual appearance and texture parameters.

Citation

Feng, X., Senin, N., Su, R., Ramasamy, S., & Leach, R. (2019). Optical measurement of surface topographies with transparent coatings. Optics and Lasers in Engineering, 121, 261-270. https://doi.org/10.1016/j.optlaseng.2019.04.018

• Journal Article Type: Article
• Acceptance Date: Apr 23, 2019
• Online Publication Date: Apr 29, 2019
• Publication Date: 2019-10
• Deposit Date: May 22, 2019
• Journal: Optics and Lasers in Engineering
• Print ISSN: 0143-8166
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 121
• Pages: 261-270
• DOI: https://doi.org/10.1016/j.optlaseng.2019.04.018
• Keywords: Mechanical Engineering; Electrical and Electronic Engineering; Atomic and Molecular Physics, and Optics; Electronic, Optical and Magnetic Materials
• Public URL: https://nottingham-repository.worktribe.com/output/2079264
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0143816619301484
• Additional Information: This article is maintained by: Elsevier; Article Title: Optical measurement of surface topographies with transparent coatings; Journal Title: Optics and Lasers in Engineering; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.optlaseng.2019.04.018; Content Type: article; Copyright: © 2019 The Authors. Published by Elsevier Ltd.