Grating shear wave aberration detection interferometer and its detection method

Abstract

The invention provides a grating shear wave aberration detection interferometer. The grating shear wave aberration detection interferometer comprises a light source, a focus lens, a filtering pinhole, a two-dimensional grating, a grating displacement platform, a diaphragm plate, a diaphragm alignment displacement platform and a two-dimensional photoelectric sensor. According to the grating shear wave aberration detection interferometer, the wave aberration of an optical system to be detected is detected; when the optical system to be detected is illuminated by the light source, the wavefront of the optical system to be detected generates an interference pattern through grating separation and shear, wavefront reconstruction is conducted on differential information generated by multiple diffraction levels in different directions through shear and interference, so that a system error correlative is obtained, and then the relevant parameters, namely, the distance between every two adjacent focusing points of different levels of diffraction light and the inclination angle of a detector, of main system error terms influencing the wave aberration detection precision of the grating shear interferometer are obtained; in this way, geometric path-length errors and detector inclination errors existing in wave aberration detection are eliminated, and the precision of wavefront reconstruction and the accuracy of wave aberration detection are improved. By the adoption of the grating shear wave aberration detection interferometer, wave aberration detection of the optical system to be detected is conducted, system errors existing during detection are eliminated, and the detection precision is improved.

Description

technical field [0001] The invention relates to a grating shear interferometer, in particular to a grating shear wave aberration detection interferometer and a detection method thereof. Background technique [0002] Grating shearing interferometer is an important form of wavefront sensor, which has the advantages of simple structure, no need for a separate reference wavefront, easy to achieve common optical path interference, and anti-environmental interference. There are systematic errors such as geometric optical path error, grating diffraction error, grating position offset and detector tilt in the grating shearing interferometer, which affect the detection accuracy of wave aberration; especially for the application of wave aberration detection in high-precision optical systems, to be The optical system under test has a certain numerical aperture (NA), and the alignment difficulty and system error of the system increase with the numerical aperture. System error is the pr...

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Problems solved by technology

Although the above method can improve the detection accuracy of wave aberration to a certain extent, it is necessary to use auxiliary means to eliminate the detector tilt error, or to perform theoretical calculations based on pre-measured corresponding data, and subtract the theoretical system from the experimental data. The system error has not been eliminated according to the actual experimental conditions, the residual geometric optical path error and the detector tilt error are relatively large, or multiple measurements are required, which increases human error, etc.

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