Detection structure and stitching error adjustment method based on blazed grating stitching technology

Abstract

Based on the detection structure of the blazed grating splicing technology and its splicing error adjustment method, two laser beams with different wavelengths are collimated and expanded and then divided into two beams by a semi-reflective half lens to form diffraction m-level detection fringes and 0-level detection fringes respectively. The former The two beams that arrive at CCD A after reflection and the incident beam pass through the splitter prism to reach the splicing grating and self-collimation reflect and then reach CCD A form interference fringes on CCD A; the 0-level detection fringes are separated by half mirrors The fringes formed by the interference of another beam reflected on the CCD B and the incident beam reflected on the CCD B; the output of the CCD A and the CCD B are respectively connected to two driving devices through computer data processing; the adjustment of the grating B Strict and reference raster A stitching. The invention maximizes the adjustment and detection of blazed spliced ​​gratings, has low cost, simple structure, and high precision, and can meet the basic requirements of high precision for splicing large-sized gratings.

Description

technical field [0001] This application belongs to the field of optical measurement, and the invention relates to a detection structure based on blazed grating splicing technology and a splicing error adjustment method thereof. In particular, it relates to a large-scale mosaic grating diffraction wavefront mosaic detection and correction method range. Background technique [0002] With the development of modern technology and scientific progress, the need for natural detection means and capabilities is getting higher and higher, and the demand for large-aperture plane diffraction gratings in special research fields such as astrophysics and high-energy pulsed lasers is becoming more and more urgent. In the field of astronomy, as the aperture of the telescope increases, it must be equipped with a corresponding large-scale spectroscopic element—the grating, in order to effectively realize the high-resolution, high-precision and high-stability detection of the telescope. For the...

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Problems solved by technology

[0005] Chinese patent application No. 201510881610.1 designed a detection technology based on light intensity and energy distribution, which adjusted the energy distribution of the spliced ​​grating, and the accuracy was low; Chinese patent applications No. 201610344818.4 and 201610344783.4 designed a splicing error detection technology for detecting spliced ​​gratings. The technology is based on the interferometric method, which uses an interferometer to obtain zero-order and interference-order fringes. This technology is mainly used for detection of ordinary diffraction gratings.

However, the large-aperture gratings used in astronomy or inertial confinement nuclear fusion are spliced ​​by blazed gratings. The zero-order energy of the blazed gratings is too weak, and the light beams generated by the interferometer cannot form interference fringes, and a strong laser is required for incident; There is mutual coupling in the adjustment dimensions of the mosaic grating. Therefore, it is too complicated and difficult to adjust the divisions according to the zero level and the interference level. The orientation of the mosaic grating is adjusted based on the variable incident angle technology generated by the prism. Small, complex structure, and many adjustment restrictions, which affect the accuracy of adjusting the splicing error

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