Virtual Coherence Scanning Interferometry

The Manufacturing Metrology Team (MMT), at the UK’s University of Nottingham, has published its 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. The developed 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.

The software was developed by Dr Rong Su at the University of Nottingham. 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 by any not-for-profit scientific research. The software was developed for research purposes but the MMT are open for any form of collaborations to develop the virtual instrument technique further.

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