Patent ID: 10012491

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.