Chinese Academy of Sciences

Difrotec Oü

Vtt-ntm Ou

Mariia Voznesenskaia

Nikolay Voznesenskiy

Tatiana Voznesenskaia

Jie Yu

Wenlong Zhang

Dongmei Ma

Chunshui Jin

Haitao Zhang

The present invention is related with the two-channel point-diffraction interferometer for testing the optical systems or optical elements. The two-channel point-diffraction interferometer comprising a laser source inducing a linearly polarized laser beam which is divided by a beam splitter to a working channel and to a reference channel whereas the one half of light as working channel is directed from the first collimator to the working collimator by a first single-mode optical fiber to keep polarization of light unchanged, and another half of light as reference channel is directed from the second collimator to the reference collimator by a second single-mode optical fiber to keep polarization of light unchanged.

Two-channel point-diffraction interferometer

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.

Large numerical aperture phase-shifting dual pinhole diffraction interferometer and its test method

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Tartu, Estonia

Mariia Voznesenskaia