The integration of measurement systems in industrial production lines and machines is currently a big challenge in measurement technology.

Machine vibrations and movement of the measuring object disturb precision measurements. However, in-process measurement intends to provide measurement data while the work piece is still in process. In this context, optical techniques offer unique capabilities.

White-light interferometery is a well-established technique for surface topography measurement. In our research work white-light interferometers were combined with additional distance measurement based on integrated laser interferometers. This enables a subsequent correction of the measurement results with respect to vibrations and linearity deviations of the depth scanner. Consequently, topography measurements with height resolution in the nanometer range are achieved even in harsh environments.

Another approach is followed with a phase-shifting interferometer that uses a color camera to reconstruct the 3D surface topography based on two RGB images recorded in a time interval of 50 µs.