The Virtual Interferometer - A Tool for the Systematic Assessment of Error-Sources in Interferometry

The knowledge of measurement uncertainties is essential for the proper assessment of product-quality, for controlling production processes and to ensure comparability with other types of metrological instruments. However, the assessment of measurement uncertainties becomes more complicated when high-precision metrology is considered. In this paper a procedure for the assessment of the measurement uncertainty of interferometers with the help of a virtual instrument, the so-called ‘Virtual Interferometer’, will be presented. In conjunction with finite element analysis the Virtual Interferometer allows to determine the influence of error-sources that cannot be modelled with commercial ray tracing software, like e.g. the thermal expansion of optical components.