A Displacement Measuring Device and Method Based on Electromagnetically Induced Transparent Atom Grating

Abstract

The invention belongs to the technical field of precision displacement measurement, and provides a displacement measurement system based on an electromagnetically induced transparent atomic grating, including a coupled laser source, a detection laser source, an offset frequency-locked optical path, an electromagnetically induced frequency-locked optical path, a reference interference optical path, and a measuring Interference optical path and photoelectric detection optical path; the present invention builds the corresponding standing wave field structure through the interference optical path, periodically modifies the refractive index in the atomic medium under the mechanism of electromagnetic induction transparency, and constructs an atomic grating with adjustable grating pitch. The channel photodetector is used for detection, and the displacement measurement through the atomic grating is realized, which improves the measurement accuracy. Moreover, the present invention breaks through the limitation that the pitch of the grating cannot be adjusted, and can reasonably set the pitch according to the different displacement degrees of the object to be measured, so as to realize a grating displacement measurement system with adjustable minimum displacement resolution, thereby adapting to various environments. Displacement measurement needs.

Description

technical field [0001] The invention belongs to the technical field of precision displacement measurement, and in particular relates to a displacement measurement device and method based on an electromagnetically induced transparent atomic grating. Background technique [0002] The grating displacement measurement technology first used the Moiré fringe phenomenon formed by the grating overlap to realize the precise measurement of displacement, but the grating based on this measurement principle is only suitable for occasions that do not require high precision. Later, with the development of grating displacement measurement technology based on the principle of interferometry, the accuracy of grating displacement measurement has been improved to the nanometer level, and it has been applied in cutting-edge equipment such as lithography machines. However, the traditional grating displacement measurement technology is mainly based on the physical grating. The grating manufacturin...

AI Technical Summary

Problems solved by technology

First of all, there are inevitably defects in the traditional grating production, which will lead to measurement errors; moreover, there is a singleness in the use of physical gratings, a single-made grating can only be used in one application scenario, and changes in measurement requirements can only be made through replacement, which will increase the cost and the complexity of the repeated adjustment system

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