Patent ID: 6937327
Filing Date: 2005-08-30
Classification: B23K,G01M

Abstract:
1. An apparatus for measuring optical properties of a diffractive optical element, comprising: a laser source which emits a laser beam; beam-splitting means of splitting the laser beam into a main beam and a reference beam; first measuring means of measuring the power or the energy of the reference beam; a test piece which splits the main beam into a plurality of split beams; a mask which allows one of the split beams to pass therethrough; mask-moving means of moving the mask along at least two axial directions in a plane perpendicular to an optical axis; second measuring means of measuring the power or the energy of the split beam that has passed through the mask; and calculating means of calculating the ratio of the power or the energy measured by the first measuring means to the power or the energy measured by the second measuring means.