Deflectometry measurement system

A system for measuring a sample by deflectometry comprising:

• a source for generating a light beam in a source plane;
• an illumination module comprising:
• a first converging optical element;
• a first selection optical element having a first aperture, said first selection optical element being positioned between said source plane and said first converging optical element;
• said illumination module being configured to generate an illumination beam from said light beam of said source;
• matrix optical modulation means in reflection, for forming a pattern from said illumination beam;
• said first aperture being configured to control angles of incidence of said illumination beam on said matrix optical modulation means in reflection;
• a Schlieren lens;
• said measuring system being configured such that said pattern is adapted to illuminate said Schlieren lens so as to obtain an angle-intensity encoding of said pattern into an inspection light beam;
• imaging means for forming an image of said sample after interaction of said inspection light beam with said sample said Schlieren lens being positioned between said matrix optical modulation means and said imaging means along an optical path of a light beam generated by said source when the latter is activated;
• matrix detection means for detecting said image of said sample formed by said imaging means;
• said system further comprising:
• beam splitting means configured to obtain from said illumination beam resulting from the illumination module:
• a first light beam transmitted by said beam splitter along a first optical path directed towards said matrix optical modulation means;
• a second light beam deflected by said beam splitter along a second optical path resulting from a reflection of said first light beam transmitted by said matrix optical modulation means,
• said first and second optical paths being perpendicular;
• a non-planar mirror positioned so as to reflect said second light beam, resulting from a reflection on said matrix phase modulation means, into a third light beam reflected to said beam splitter along a third optical path.