A three-dimensional detection method of structured light micro-nano structure based on composite grating

Abstract

The invention is a three-dimensional detection method of a structured light micro-nano structure based on a composite grating. A composite grating combined with a horizontal sinusoidal grating and a sinusoidal grating inclined at a certain angle θ is used to project structured light on the surface of the object to be measured. During the process of horizontally scanning the object to be measured, the CCD synchronously collects the modulated light from the conjugate optical path through the beam splitter prism. In the fringe image sequence, the grid line direction of the horizontal grating is perpendicular to the horizontal scanning direction, and the entire field modulation degree of the object is extracted to calculate the horizontal displacement to achieve high-precision pixel matching of the image sequence; the focal plane position of the tilted grating imaging is tilted and fixed. During the horizontal scanning process, the phase shift and vertical scanning can be continuously and automatically synchronized. The tilted grating is used to extract the single-point modulation degree of the object, and the height information is obtained to realize high-precision micro-nano three-dimensional detection. The invention only needs to scan the object to be measured horizontally to realize a large-scale and high-efficiency three-dimensional measurement process, and has a good application prospect in the field of micro-nano detection.

Description

technical field [0001] The invention belongs to the technical field of optical microscopic imaging and precision detection, and in particular relates to a three-dimensional detection method for structured light micro-nano structures based on composite gratings. Background technique [0002] Micro-nano devices refer to functional devices with a scale of micron and nanometer. The application in the technical fields of microelectronics, biotechnology, aerospace, and metamaterials has developed rapidly, which has greatly promoted modern life and social production. It will be a hot spot in the development of science and technology strategy in the next period. The three-dimensional appearance of micro-nano devices is directly related to the performance characteristics, reliability and functional analysis of the product. High-precision and fast micro-nano detection methods and technologies are important means to obtain the three-dimensional appearance of micro-nano structures, and ...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the disadvantages of low efficiency and complex structure in the existing three-dimensional shape detection method of micro-nano structure, the present invention designs a three-dimensional detection method of structured light micro-nano structure based on composite grating: in this method, A composite grating combined with a horizontal sinusoidal grating and a sinusoidal grating inclined at a certain angle θ is used to project structured light on the surface of the object to be measured. During the process of horizontally scanning the object to be measured, the CCD synchronously collects the modulated light from the conjugate optical path through the beam splitter prism. The fringe image sequence, combined with the continuous 3D reconstruction algorithm, can reconstruct the 3D surface shape of the micro-nano structure, realize the large-scale detection of the continuity of the micro-nano structure, and can be applied to the online detection process of the micro-nano structure, and the detection accuracy can reach the nanometer level

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