Optical component for use in interferometric measuring device, has diffractive auxiliary unit converting irradiated light into auxiliary waves, where fictitious surface is positioned in auto-collimation position concerning spherical waves

摘要

The optical component (44) has a corrugated unit for forming a part of irradiated measuring waves (20) into spherical waves with a known radius. A diffractive auxiliary unit is used for converting irradiated light into auxiliary waves, which are focused on a fictitious spherical surface. The fictitious spherical surface is positioned in auto-collimation position concerning the spherical waves. The fictitious spherical surface includes a radius of curvature. Independent claims are also included for the following: (1) an interferometric measuring device comprising a shifter (2) a test specimen comprising an edge surface (3) a method for measuring a radius of curvature of a spherical surface of a test specimen.