Interferometric measuring device e.g. Fizeau or Michelson interferometer, for e.g. measuring spherical or aspherical optical surface of test object, has diffractive surfaces that correspond with optical surfaces that are to be measured

摘要

The device has an optical unit (102) that comprises a reference surface (103), and a diffractive optical unit (105). The diffractive optical unit comprises two different diffractive structures (112, 113). One of the diffractive surfaces corresponds with an optical surface (107) that is to be measured and another diffractive surface corresponds with another optical surface (109) that is to be measured.