Manufacturing Metrology Team

MMT publishes virtual coherence scanning interferometer


VCSI workflow and digital twin

The MMT has published our work on development of a virtual instrument for coherence scanning interferometry.

Uncertainty evaluation for optical measurement of surfaces with complex topography (such as freeform and biomimetic artificial surfaces) is an open issue in industrial metrology capability. A promising approach to uncertainty evaluation is to use a “virtual instrument” – the digital twin of a specific real instrument. This approach has been successfully used to provide uncertainty evaluation in the contact coordinate metrology world, but the virtual instrument is not yet available in the context of optical surface metrology. This software is the first virtual coherence scanning interferometer (VCSI) for surface measurement. The VCSI is fully powered by physical models derived from first principles and provides deterministic measurement result for surfaces with complex topography as is obtained using a real instrument.

The primary function of the virtual instrument is task-specific uncertainty evaluation; it can also be used to predict the instrument response and measurement result, in order to assess the feasibility of an instrument for a specific surface, find optimal instrument settings, improve the understanding of the measurement process and test new instrument configurations. For more technical details of the VCSI technique, please consult Su R and Leach R K 2021 Physics-based virtual coherence scanning interferometer for surface measurement Light: Adv. Manuf. In press

This software was developed by Dr Rong Su at the University of Nottingham (email: The development was supported by the Engineering and Physical Sciences Research Council [grant numbers EP/M008983/1; EP/R028826/1]. The software can be used without limitations in any not-for-profit scientific research. The only request is that in any publication where the software is used the source of the software be acknowledged and proper references be made.

This software was developed for research purposes. We are open for any form of collaborations to develop the virtual instrument technique further. Any feedback is very welcome.

The software user guidance is available here and the software itself is available for download as a .zip file here.

Posted on Friday 26th February 2021

Manufacturing Metrology Team

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