Abstract: A diffraction interferometer includes a reference light passage, a test light passage and a pinhole substrate. The pinhole substrate includes a test pinhole and a reference pinhole. The diffracted wavefront emitted from the test pinhole is reflected by the optical component to be tested adjacent to the pinhole substrate and a converge adjacent to the reference pinhole. The diffracted wavefront includes surface shape information of an optical component to be tested that is reflected by the pinhole substrate. Interference with the diffracted wavefront is emitted by the reference pinhole and forms interference fringes. The large numerical aperture phase-shifting dual pinhole diffraction interferometer adopts a dual pinhole substrate and a illumination manner with two converged light paths to enable the separation of the reference light and test light, to prevent disturbance between the two light paths, which would induce the change of interferogram status during phase-shifting.

Abstract: The present invention relates to a large numerical aperture phase-shifting dual pinhole diffraction interferometer and its test method, the diffraction interferometer comprises: reference light passage, test light passage and pinhole substrate; wherein, said pinhole substrate comprises test pinhole and reference pinhole; the diffracted wavefront emitted from the test pinhole would be reflected by the optical component to be tested near the pinhole substrate and converge near the reference pinhole, and said diffracted wavefront comprising surface shape information of optical component to be tested, would be reflected by the pinhole substrate and interference with the diffracted wavefront emitted by reference pinhole, forming interference fringes.

Abstract: The present invention is related with the optical instrument such as interferometer for testing the optical systems and samples whereas the optical instrument comprises the laser (1) for generating the laser beam which passes the beam expander (2), beam-splitter (23) dividing the laser beam to a working light beam and reference light beam, focusing objectives (3, 7), flat glass plate (4) with one side coated by thin metal highly reflecting coating with the pattern including a pinhole, computer (12), CCD camera (13), tested part or optical system (6). In addition the optical instrument comprises at least two flat mirrors (24, 25), observation objective and at least one stop (20) placed between the beam-splitter (23), flat mirrors (24, 25) and/or focusing objective (7).