High-accuracy wide-range double-layer nano-grating micro displacement detection device

Abstract

The present invention relates to a high-accuracy wide-range double-layer nano-grating micro displacement detection device. The micro displacement detection device includes a displacement sensing module, a processing unit and a display unit; the displacement sensing module is connected with the display unit through the processing unit; the displacement sensing module comprises double nano-grating layers which can move relative to each other; the double nano-grating layers include a movable nano-grating array and fixed nano-gratings; a plurality of nano-grating regions are spliced to form the movable nano-grating array; certain intervals are left between the plurality of nano-grating regions; the processing unit includes a subdividing circuit; and the subdividing circuit can improve the resolution of the output signals of a photodetector array. The grating period of the micro displacement detection device is smaller than the grating period of an existing micrometer-scale device, and therefore, the micro-displacement detection precision of the gratings is improved; the grating regions of the movable nano-grating array are spliced, so that the range of the micro displacement detection device is wider. The micro displacement detection device has the advantages of compact overall structure, high miniaturization degree and higher practicality.

Description

technical field [0001] The invention relates to the technical field of micro-displacement detection, in particular to a high-precision and large-range double-layer nano grating micro-displacement detection device. Background technique [0002] The vector diffraction theory is one of the methods for analyzing the diffraction characteristics of gratings. It gives an accurate solution to the diffraction characteristics of gratings. After 20 years of development, it is relatively mature and can be divided into two categories: integral methods and differential methods. The integral method is suitable for the analysis of diffraction characteristics of gratings with continuous surface type, and the solution process is complicated, while the differential method is more suitable for the analysis of diffraction characteristics of gratings with discontinuous and discrete surface characteristics, and the solution process is relatively simple. Differential methods mainly include Rigorous...

AI Technical Summary

Problems solved by technology

[0004] The current grating displacement sensor is mainly based on the Moiré fringe displacement sensor, but the Moiré displacement sensor uses a grating with a large grating pitch, which is difficult to improve the resolution and has a large volume, so it is difficult to measure the micro-displacement of in-plane motion in the micro-nano structure

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