Virtual optical instrument to model coherence scanning interferometry (Invited Paper)

In optical metrology, the growing demand for high-quality digital twins of surface measurement technologies, driven by increased applications of three-dimensional microscopy and imaging, is met through the development of virtual instruments (VIs). A VI replicates an optical instrument, allowing for enhanced understanding, optimisation and uncertainty evaluation of measurements. Coherence scanning interferometry (CSI), a common technique for accurate surface topography measurement, can be modelled using both approximate and rigorous scattering models. While approximate models are computationally efficient, rigorous models based on Maxwell’s equations offer high-accuracy solutions for complex light-matter interactions. Our study employs virtual coherence scanning with both model types, comparing their results, and proposing a procedure for uncertainty evaluation.