Adapting multi-lateral shearing interferometry to new measurement needs: metasurfaces and segmented surfaces

The aim of this lecture is to show how the consideration of very specific measurement requirements, related to segmented surfaces and metasurfaces, has enabled a generalist multilateral shearing interferometer to evolve into new innovative devices. This has enabled state-of-the-art performance to be achieved, in particular by exploiting in the design a priori knowledge of the objects to be measured. Performance is illustrated here by a comparison of measurements on a canonical object, a PTT-111 deformable mirror from the company Iris AO, with a reference Phase Shifting Interferometer from the community.