Fundamental Research And Realization Of Digital Holographic Microscopy

Digital holographic microscopy (DHM) is a novel microscopic technology which is based on digital holography principle. It enables one to compute simultaneously the intensity and the phase distribution of the propagated wave. Moreover, the numerical procedure allows for the correction of the optical aberration introduce by the microscope objective and other imperfections of the optical aberration. The method is completely non-invasive and fast acquisition of dynamic information is possible. DHM has the widespread prospect in the micro domain. It may use in the biological cell observation, micro particle imagery and track, polymer granule growth examination, micro mechanical and electrical and microcircuit examination and so on many domains.In this paper, we discussed various microscope principle of DHM based on the theory of digital holography. Each kind of condition should consider which to digital holography concrete experiment in has done the earnest careful analysis research. Holographic enlargement and holographic microscope, two main methods, were discussed, and the pre-enlargement digital image plane holography was studied with emphasis. The propagated wave of onion epidermal cells was recorded and reconstructed by using the four-step phase-shifting and digital image plane holography. Through the compensation of phase errors and phase unwrapping process, we obtained the sample appearance structure.The present paper main innovation work is as follows:1 , Elaborated the basic principle of holographic microscope which is embarked from the point-source hologram, and promoted the magnification formula and the image position formula. Three ways of holographic enlargement were produced: Reduces the hologram; Short wave length record, long wave length reconstruction; Chooses the appropriate reference and reconstruction wave surface radius of curvature. We proved the feasibility of these three kinds of holographic enlargement method through the computer simulation and the experiment.2, The pre-enlargement digital image plane holographic microscopy, a novel method, was proposed, and the image plane hologram mathematical expression was theoreticallypushed. The use of image plane holography not only may abbreviate the diffraction process of reconstruction, simplifies the holography steps, and also reduced the errors introduction in diffractive reconstruction.