Patent ID: 6573997
Filing Date: 2003-06-03
Classification: G01B,G01M,G03F

Abstract:
A hybrid shearing and point diffraction interferometer system for testing an optical element that is positioned along an optical path comprising:a source of electromagnetic energy in the optical path; a first beam splitter that is secured to a device that includes means for maneuvering the first beam splitter in a first position wherein the first beam splitter is in the optical path for dividing light from the source into a reference beam and a test beam and in a second position wherein the first beam splitter is outside the optical path; a hybrid mask which includes a first section that defines a test window and two or more reference pinholes and a second section that defines a second beam splitter wherein the hybrid mask is secured to a device that includes means for maneuvering either the first section or the second section into the optical path positioned in an image plane that is created by the optical element; and a detector positioned after the hybrid mask along the optical path.