Tilted-Wave Interferometer (TWI) as Example for Hand-in-Hand Calibration of Real and Virtual Experiments

The optical industry uses aspheres and free-form surfaces in modern optical systems, which, however, place very high demands on metrology. Optical measurement techniques have a prominent role to play here, as they do not damage the measurement objects. The industry urgently needs traceability in optical asphere/free form metrology, which is not yet available with the demanded accuracy. Further research projects can therefore be expected with respect to aspherical and free-form metrology development at the international level.

The further development of the TWI concept is integrated in the "PTB's work and research programme" in topic area 5: Length, dimensional metrology. The project has a particular impact on the promotion of the German and European optical industry and the associated manufacturers of measuring instruments. Aspheres and free-form surfaces are an outstanding future-oriented development in optical systems and have an impact on high-end camera systems, industrial camera systems and also camera applications in the automotive and consumer sectors. The goal of PTB is to achieve a highly accurate, traceable measurement by combining real and virtual experiment. This creates the possibility to trace back industrial measuring technology for optical aspheres and free-form surfaces which enables a much more precise production of such surfaces and will in particular be very positive for the German or European competitiveness.