The Research On Key Technologies Of Reflective Digital Holography Microscopy

Digital holographic technology has developed rapidly in recent years.In the macroscopic field,digital holographic technology includes holographic images,digital holographic grating technology,etc.In the microscopic field,digital holographic microscopy technology which can achieve quantitative,fast,non-destructive,non-contract measurement has the rapid development.Based on these characteristics,it makes digital holographic microscopy technology widely used in micro-machinery,micro-electronics,micro-optical components,bio-medicine,space particle measurement and many other fields.In many studies of digital holographic microscopy,there is the influence of high-order phase distortion on the reconstruction image,and there are some errors in the construction and adjustment of the test device,which makes the research become difficult.In this paper,this paper designs and improves the reflective digital holographic macroscopic optical path,which mainly eliminates the effects of phase distortion.By designing a reflective digital holographic microscope,it will improve the accuracy of the experiment and make the research and research results more accurate.This article first discusses the minimum recording distance that satisfies the Nyquist sampling theorem and the separation condition of the reproduced image during digital holographic recording based on digital holographic microscopy technology.And it studies three commonly used digital reconstruction algorithms and compares the three algorithms by experimental verification.It draws the conclusion that the angular spectrum diffraction algorithm has a smaller calculation amount and shorter calculation time than the convolution algorithm,and has a higher imaging quality than the Fresnel approximation algorithm.Secondly,by improving the typical reflective digital holographic optical path,the secondary phase distortion is basically removed,and the primary phase distortion is basically eliminated by the frequency domain filtering method.Based on the improved digital holographic microscopy optical path,the position and size of each optical component have been determined when designing the reflective digital holographic microscope.The threedimensional modeling of the reflective digital holographic microscope is performed by using 3D modeling software.It makes us obtain the entire production plan of the reflective digital holographic microscope.The selection of optical components determines the feasibility of making a reflective digital holographic microscope.Finally,it builds an improved digital holographic microscopic optical path,and the dynamic morphology of the MEMS is measured based on the image plane digital holographic microscopy.The test results of the German Ploytec Doppler laser micrometer are compared with the experimental results to verify correction of the optical path of the improved reflective digital holography microscopy.