Super-resolution Of Digital Holography Microscopic Imaging Theory And Experimental Research Based On Annular Aperture Filter

Digital holography is a new imaging and measuring technique,which achieved high degree of integration in optical,optoelectronic technology and computer technology.As an important application of digital holography,digital microscopy holography not only has the advantages of non-contact,no-damage,whole viewing field,simple reconstruction,flexible processing and convenient storage,but also obtains the quantitative intensity and phase distribution of three-dimensional micro-structure at the same time.So,in recent years,digital holography microscopy becomes a kind of important microscopic imaging technique with wild application prospects.Digital holography microscopy is one of applications of digital holography.In traditional optical microscopy,the imaging resolution,however,due to optical diffraction effect and the influence of limited aperture,is limited in a certain.It's difficult to meet microscopic imaging development.Therefore,how to improve the resolution of the optical microscopy system for people to explore the finer cellular structure and function is an important and urgent task.According to the theory of scalar diffraction,a new far-field super-resolution optical microscopic imaging method by the way of optical pupil filter or annular pupil filter is introduced in digital holographic microscopy.This paper focus on the imaging method and system of the super-resolution optical microscopy included in the theoretical analysis,numerical simulation and experimental verification for this kind of type amplitude pupil filter.In this article the resolution detection is similar to the light intensity rather than the phase.First of all,the pupil function of pupil filter and annular pupil filter is presented,and then according to the theory of scalar diffraction the diffracted distributions toward these two kinds of pupil filter are deduced by Fraunhofer formula.These distributions are related to 1 order Bessel function function.Secondly according to the given pupil function program is made in MATLAB to draw pupil filter transmittance distribution,diffracted distribution about these two filter in two-dimensional and three-dimensional manner.Further the resolution of the optical microscopy is discussed in detail.By simulating the superposition of two point distribution,it could be concluded that the resolution of the microscopic system could be improved by means of these two pupil filter.Finally,to design a digital holographic microscopy system,the Mach-Zehnder interference configuration with pupil filter is equipped,The holographic experiment is conducted with respect to USAF1951 resolution board,plant cells and blood cells.The holograms are recorded.Reconstructed is made by +1 level on a computer.Experiments prove that with annular pupil filter,the high frequency part of larger cells become more obvious.The collective effect of super resolution is not very ideal.