Patent ID: 7880897
Filing Date: 2011-02-01
Classification: G01B,G01M

Abstract:
1. A light wave interferometer apparatus comprising: a luminous flux separation and composition unit that separates a luminous flux sent from a light source into two of a first luminous flux going in a direction of a measured sample having a surface shape to be measured and a second luminous flux going in a direction of a reference sample and composes a light of the first luminous flux returning from the measured sample with a light of the second luminous flux returning from the reference sample so as to generate an interference light which forms an interference fringe image on an imaging body arranged at a position based on information of a surface shape of the measured sample; a first basis spherical lens arranged between the luminous flux separation and composition unit and the measured sample and having a first basis spherical surface opposed to the measured sample, the first basis spherical lens making the first luminous flux from the luminous flux separation and composition unit incident on a surface of the measured sample and returning the first luminous flux reflected on the surface of the measured sample to the luminous flux separation and composition unit; and a second basis spherical lens arranged between the luminous flux separation and composition unit and the reference sample and having a second basis spherical surface opposed to the reference sample, wherein a radius of curvature of the second basis spherical surface is the same as that of the first basis spherical surface, the second basis spherical lens making the second luminous flux from the luminous flux separation and composition unit incident on a surface of the reference sample and returning the second luminous flux reflected on the surface of the reference sample to the luminous flux separation and composition unit, wherein the measured sample is an aspherical optical element, and the reference sample is an aspherical optical element and has a reference shape of the measured sample.