Flatness calibration of XY translation stages through modal parameterization

International audience; The issue of this document is to improve the metrological performances of XY translation stages of an optical profilometer Altisurf©. We propose a calibration protocol to correct the systematic geometrical errors, for example pitch and roll, related to geometrical errors of guiding system. It consists in measuring a flat glass with λ/10 (flatness ≈ 60 nm) and a very high precision optical sensor (u=0.06 μm). The correction surface is then parameterized by an original method of parameterization: the modal parameterization, to differentiate the systematic and random geometrical errors. The modal parameterization of a surface results from the Discrete Modal Decompositio…