Research On Multifunctional Microsensors Based On Self-imaging Of Micro-nano Gratings

The high-performance motion parameter sensors serve as vital components in precision positioning systems and find widespread application in precise mechanical inspections and measurement devices,such as precision workbenches.Over the past few years,sensors based on different principles like electromagnetic effects,laser interference,Moiré fringes,and grating diffraction interference have been employed for the measurement of motion parameters like vibration and angle in the aforementioned application domains.Among several approaches,the grating-based motion parameter detection method has garnered continuous attention due to its high resolution,excellent stability,and multi-degree-of-freedom measurement capability.However,this method typically utilizes gratings with periods exceeding 10 μm,resulting in lower resolution and posing challenges in achieving miniaturized designs.The development of positioning systems for integrated equipment like lithography machines,high-precision machine tools,and electron microscopes necessitates the measurement of motion parameters such as angle and vibration,calling for the development and design of high-performance,multifunctional,miniaturized sensors.This article focuses on the study of angle and vibration measurement based on the self-imaging effect of a dual-grating structure.The main research contents are as follows:The current status of the development of measurement technologies for motion parameters such as angle and vibration is analyzed,and the measurement methods of several mainstream vibration and angle displacement sensors at present stage are compared.The advantages and problems of existing detection technologies are summarized.By fully utilizing the technical characteristics and application advantages of grating sensors,a design concept for a miniaturized,high-performance,and multifunctional sensor is proposed,which employs the self-imaging effect of micro-nano gratings.By analyzing the self-imaging theory of gratings,the mechanisms for in-plane vibration and angular sensitivity of dual-grating structures are explored.A measurement model for vibration and angle using dual gratings is constructed,and simulation analysis is performed on the double-layer grating structure employed in this sensor.It is observed that for in-plane vibration displacement,the total transmission of the dual-grating structure varies sinusoidally with the displacement.On the other hand,for the double-layer grating structure with changes in the pitch angle of the upper grating,the total transmission of the dual-grating structure exhibits an approximately linear relationship with the relative pitch angle between the two gratings.To benchmark against existing vibration sensors,the core parameters of the vibration sensor are determined.Based on the in-plane vibration simulation model and the requirements of the core parameters,the optical path is designed,and experimental system testing is conducted to evaluate the key performance indicators of the sensor.Through experimentation,it is demonstrated that the sensor,using a grating with a period of 3 μm,achieves a displacement resolution of 0.737 nm within a range of 1 mm for in-plane vibration displacement.Additionally,the experimental results indicate that the sensor is capable of detecting in-plane vibration frequencies below 900 Hz.To benchmark against existing angle sensors,the core parameters of the angle sensor are determined through simulation analysis.In the simulations,different parameters of the grating,such as grating period,number of grating lines,and distance between the two gratings,are varied to demonstrate the tunable sensitivity and measurement range of the angle sensor based on the self-imaging effect of the dual-grating structure.Furthermore,experimental test results show that the designed sensor achieves a sensitivity of 0.19 m V/arcsec and a relative sensitivity of 0.27%/arcsec within a range of 396 arcseconds.These results indicate that the proposed sensor possesses a compact structure and high sensitivity.In conclusion,we have summarized and provided a prospect for the research work described in this article.Through a thorough analysis of the specific tasks undertaken,we have ultimately summarized the detection performance of the sensor and its significance in the current landscape of displacement measurement.Furthermore,drawing upon the current research achievements,we have offered a glimpse into future research directions and proposed areas of optimization.Ultimately,we have provided a concise summary and an outlook on the future of the discussed research work,highlighting its contributions to the field of displacement detection.