Research On Micro/nano Structure Detection Method Based On Light Field Imaging Principle

With the continuous development of micro-nano technology,various micro-nano devices have emerged,which are widely used in the fields of metamaterials,national defense research,and biotechnology.Micro-nano technology has become one of the indicators to measure the state's cutting-edge science and technology.The detection technology and micro-nano processing technology complement each other,which is an important guarantee for processing accuracy.The detection method is constantly developing in the direction of fast,high-precision,three-dimensional and large field of view.In recent years,with the development of light field cameras,as an important branch of the field of computational optical imaging,light field imaging technology not only records the spatial intensity of three-dimensional objects,but also captures the angular information in the physical world.This provides a new way to solve computer vision problems such as 3D reconstruction,significant area detection,and target recognition.The characteristics of fast,high-precision,three-dimensional and large-field detection of light field imaging technology have attracted more and more attention,and from the original light field imaging extension application to micro-nano detection,it has become a new method of micro-nano detection.Therefore,this paper proposes a micro-nano structure detection method based on the principle of light field imaging,and conducts in-depth theoretical and applied research on the principle of light field detection,the method of extracting the depth of the light field,the design and processing of the microlens array,and the specific research work.And the results obtained are as follows.First,study the current theoretical results of light field imaging,combined with simulation experiments,to study the optical model and mathematical model.The basic processing method of the light field image is analyzed,and the actual light field image and the simulated image are combined for analysis.The light field refocusing,the optical field polar plane image(EPI)extraction,the light field image viewing angle transformation,and direct imaging are analyzed.Secondly,the depth chord depth extraction method based on light field refocusing and the parallax matching depth extraction method based on EPI image are analyzed in depth.The double cues depth extraction algorithm combining light field data analysis and defocusing is proposed.Overcome the shortcomings of large calculation,edge effect,low precision and burr.Thirdly,the exposure threshold characteristics of the photoresist are fully analyzed,and the exposure threshold shape control model is deeply analyzed.The relationship between the relative concentration of the photoresist and the exposure depth is analyzed..The simulation of the influence of the three characteristic parameters of the photoresist on the surface shape during the exposure process was carried out,and the model was simplified in the case of a small exposure amount.Finally,the preparation of the microlens array is completed by a moving mask method.Fourth,from the perspective of system research,the sensor pixels are fully utilized on the optical path to match the parameter relationship between the main lens,the microlens array and the sensor.Fully consider lighting,thickness adjustment on the machine.The software satisfies the basic needs,and intuitively visualizes,refocuses,and deeply extracts the light field data.And the experimental test,which not only confirms the feasibility of the method,but also broadens the application field,realizes the systematic research from the theoretical analysis to the detection system,and lays a solid foundation for the subsequent application.Fifth,the application of the micro-lens array,the core component of the detection system involved in this paper,is explored.In this paper,an interferometric imaging method based on microlens array is proposed,and the imaging model is deeply studied,and a simulation digital model is established.The imaging simulation analysis is performed on the imaging method.Inject fresh blood into the field of interference imaging.In view of the micro-nano structured light field detection technology,this thesis has carried out in-depth theoretical research,and proposed specific solutions and solutions for measuring optical path,data processing method,microlens array design and processing,etc.The field provides a reliable reference.