Effects of defocus on the transfer function of coherence scanning interferometry
journal contributionposted on 2018-04-20, 10:54 authored by Rong Su, Matthew Thomas, Richard K. Leach, Jeremy CouplandJeremy Coupland
© 2018 Optical Society of America. Coherence scanning interferometry (CSI) offers three-dimensional (3D) measurement of surface topography with high precision and accuracy. Defocus within the interferometric objective lens, however, is commonly present in CSI measurements and reduces both the resolving power of the imaging system and the ability to measure tilted surfaces. This Letter extends the linear theory of CSI to consider the effects of defocus on the 3D transfer function and the point spread function in an otherwise ideal CSI instrument. The results are compared with measurements of these functions in a real instrument. This work provides further evidence for the validity of the linear systems theory of CSI.
This work was supported by the Engineering and Physical Sciences Research Council (EPSRC) (EP/M008983/1); European Metrology Programme for Innovation and Research (EMPIR) project FreeFORM (15SIB01).
- Mechanical, Electrical and Manufacturing Engineering
Published inOptics Letters
Pages82 - 85
CitationSU, R. ...et al., 2018. Effects of defocus on the transfer function of coherence scanning interferometry. Optics Letters, 43(1), pp. 82-85.
Publisher© Optical Society of America
- VoR (Version of Record)
Publisher statementThis work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/
NotesThis is an Open Access Article. It is published by Optical Society of America under the Creative Commons Attribution 4.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/