Research On Digital Holographic Microscopic Imaging System

Digital holography is a technology involving many disciplines such as optics,optoelectronic technology,holography,and computer technology.It has the advantages of non-contact,no damage,full field of view,flexible processing,and convenient storage.digital holography and microscopy technology are combined in Digital holographic microscopy to perform quantitative phase microscopic measurement of microscopic objects,and has wild application prospects in the fields of medicine and industrial manufacturing.Nowadays,the research of digital holographic microscopy is becoming more and more mature.Although the technology is developing rapidly,some problems still need to be solved.,poor anti-interference ability and other defects,but due to the characteristics of the spectroscopic element,it is difficult to adjust the separation distance between the object light and the reference light.The research on the improvement of the secondary distortion of the reflection-type digital holographic microscope imaging system is more dependent on the later numerical compensation,and it is difficult to obtain a better compensation effect.In this thesis,through in-depth research on two types of digital holographic microscope systems,transmission type and reflection type,two improved optical path systems are designed.The main contents include:In part of the introduction,the basic principle of digital holographic microscopy is introduced,including the basic imaging principle,the conditions that need to be met during recording,the reproduction algorithm and the principle of phase unwrapping,and the principle of digital holographic microscopy sharps measurement is analyzed from transmission and reflection,which provides theoretical support for the construction of digital holographic microscope system,hologram recording and numerical reconstruction of intensity map and phase map.A transmissive common path off-axis digital holographic microscope system is proposed in this thesis.The main work includes: On the basis of theoretical research,the imaging and light wave polarization changes of the system are analyzed,and the adjustment spectrum separation distance and method for fringe contrast.Select the main optical components in the system,and use Solidworks 3D modeling software to design and manufacture the spectroscopic interference module.The system is used to collect holographic images of different experimental samples,which verifies the feasibility of the system adjustment method and tests its imaging ability.Solidworks software is used to design each package structure,and the assembled overall model is displayed.In addition,a reflective telecentric regimen digital holographic microscope system is proposed.The main work includes: The accurate measurement accuracy of the telecentric regimen system is reflected through the comparative analysis of three telecentric systems.The designed system structure is compared with several other reflective digital holography systems,and the advantages of the system in phase distortion correction are proved.On the basis of theoretical research,the imaging process of the system and the principle of distortion correction are further analyzed.The reflective telecentric regimen digital holographic microscope system is built with cage structure and packaged.The built system is used for mirror and resolution plate imaging,and the phase distortion correction capability and quantitative phase imaging capability of the system are verified.