Investigation Of Exact Phase Reconstruction Algorithm And Expeiments In Digital Holographic Microscopy

Digital holography is a new imaging and measurement technique, which achievedhigh degree of integration about optical, optoelectronic technology and computertechnology. As an important application of digital holography, digital microscopyholography not only has the advantages of non-contact, no damage, whole viewing field,simple reconstruction, flexible processing and convenient storage, but also obtains thequantitative intensity and phase distribution of three-dimensional microstructure at thesame time. So in recent years digital microscopy holography becomes a kind ofimportant microscopic imaging technique with wild application prospects. But atpresent, there is a key problem need to deal with in the digital microscopy holography,which is the phase reconstruction accuracy not enough high. The problem mainlyreflected in low imaging resolution, not ideal imaging quality, not completely phasedistortion compensation and so on. Therefore, the mainly purpose of this paper is tosolve the existing key problem.Through theory analysis, computer simulation and experiment demonstration, thisthesis focuses on the research of the high-precision phase reconstructed algorithm indigital microscopy holography, and obtains a series of achievements in some keynumerical reconstructed algorithm, systems resolution, high-precision phasereconstructed algorithm and imaging different samples. The main contents and thesignificant explanations are as follows.1. Firstly, the recording and reproduction process of digital microscopy holographyare analyzed, in which the three common reconstructed algorithms are introduced, andalso the characteristics and range of the three algorithms discussed.2. The method of improving systems imaging quality is mainly studied. At first,according to the location of CCD, the pre-magnification digital micro-holography isdivided into six kinds of recording system, and from the aspects of imaging resolution,imaging quality and ease of implementation analyzed and compared, the digitalimage-plane holographic microscopy (DIPHM) is an optimization imaging system.Secondly, combining this system with based on annular aperture illumination superresolution imaging technique, through the analysis of imaging process, based on annularaperture illumination DIPHM has higher resolution, and the computer simulation resultsproves the correct of the theory analysis. 3. Several key technologies are analyzed in high-precision phase reconstructedalgorithms. First of all, a homomorphic signal processing technique based on firmreal-time nonlinear reconstruction algorithm researched is verified by computersimulation and experiment, the result shown that: the new way has highly reconstructedspeed and precision. Several classical phase unwrapped algorithms are analyzed andcompared, then the principle and the scope of two-step phase distortion correctionalgorithm and automatic phase aberration compensated method are discussed andautomatic phase aberration compensated method is taken to improve anti-noise ability.The above theory analysis is verified by experiment.4. The above algorithms are applied to different digital holographic phase contrastimaging system and biological cells phase measurement, through the experimental studyof the biological cells phase measurement, the superiority of the equal curvature ofobject light and reference light DIPHM and the value of microscopic application comesout.