Design And Testing Of Miniaturized Out-of-plane Displacement Sensor Based On Self-imaging Effect Of Micro-nano Gratings

High-precision micro-displacement measurement is crucial for precision mechinery,microelectronics manufacturing,aerospace,biotechnology,military and other scientific and technological applications.Over the past years,optical micro-displacement technology has been widely developed and researched because of its high resolution,strong anti-interference and easy operation.Among them,the grating displacement sensor is popular because its resolution is mainly affected by its period,when the smaller the grating period,the higher the corresponding resolution,but the processing process difficulty becomes elevated while the nano grating period is small,and the micron grating processing process is relatively simple,but its resolution is lower.Based on the comprehensive consideration of process difficulty and sensor design indicators,this paper uses a double-layer micron grating to design an out-of-plane displacement detection sensor.,and analyzes the key technologies involved in it.The design is based on the self-imaging effect of micrometer gratings,and uses a four-quadrant detector combined with high-magnification electrical subdivision to achieve high-resolution out-ofplane displacement detection.In this paper,the research is carried out according to the following aspects.:Firstly,the commonly used out-of-plane displacement measurement methods are investigated and analyzed,and the detection principles are analyzed,the corresponding resolutions and the achievable ranges are given,and then the limitations of these methods in terms of high resolution and range are discussed and summarized.Then,the limitations of these methods in terms of high resolution and range are discussed and summarized.A detection method for out-of-plane displacement detection using grating self-image effect is proposed.Secondly,the diffraction and interference effects of single-layer grating in fluctuation optics are summarized,the triggering conditions and spatial field strength distribution of the grating self-imaging effect are analyzed based on Fourier optics principle,the displacement detection model theories of single grating and double grating structures are analyzed respectively,and the design scheme of double grating out-of-plane displacement sensor is proposed.Thirdly,the design structure of optical displacement detection sensor based on grating selfimage effect is studied,the working principle of the detection structure is introduced,and the indicators of the displacement sensor are designed and studied,the corresponding simulation of the designed optical module is carried out,the suitable values of grating period,light source wavelength,,duty cycle and other parameters are obtained through continuous simulation and optimization,the module design of the dual-grating detection system is completed,the module design of the dual-grating detection system is completed,so as to prepare for the construction of the designed system and the performance data test data collection..Finally,the designed out-of-plane displacement detection system is set up and texted.In the experiment,the high-precision photoelectric detection technology is used to realize the sinusoidal signal output of the displacement signal,and the cross-scale improvement of the detection resolution of the system is completed by the high-magnification subdivision circuit,the experimental results show that the resolution of the off-surface displacement sensor is11.23 nm,and the range reaches 1mm.Compared with traditional detection techniques,this structure has the advantages of simple optical circuit design and compact system structure,and which provides a theoretical and technical basis for miniaturized and highly integrated system applications.