Super-resolution Of Digital Holography Microscopic Imaging Theory And Experimental Research Based On Using Bottle Beam

Digital holographic microscopy(DHM)introduces a micro optical imaging system in the digital holographic optical path.The microscopic sample is amplified by a microoptical system and interferes with reference light,and the interferogram is stored and transmitted to the computer through recording medium.The amplitude and phase information of the magnified image are obtained through numerical reconstruction of computer software.Because of the resolution of charge-coupled device(CCD)and the resolution limit of the optical system,transverse resolution of microscopes are mainly dependent on the numerical aperture of the microscopical lens and the wavelength of the light wave,and the resolution is still limited within the limit resolution range.In order to break through this restriction,a dark field digital holographic microscopy is proposed on this basis.This method combines the advantages of high resolution of dark field microscopy with the characteristics of digital holography,which makes the digital holographic microresolution improved effectively.First of all,this paper introduces some basic theories related to the paper,and introduces the basic principles of the dark field microscopy and digital holographic microscopy,and discusses the methods to improve the resolution of the dark field microscopes.Secondly,the tunability of the bottle beam's annular size is analyzed,and the factors that affect the size of the bottle beam and the ratio of the ring to diameter ratio are discussed.The influence of annular light with different ring to diameter ratio on the resolution of microscopic imaging is analyzed.Finally,by using the bottle beam to improve the dark field microscopic illumination,a dark field digital holography based on the bottle beam illumination is proposed,and the special distribution of the intensity of the cross section of the bottle beam is used as the illuminating light of the dark field digital holographic microscopy.The corresponding dark field digital holographic microscopy system was built,and550 nm polystyrene microspheres were used as experimental samples.Through comparison and analysis of the digital holographic image reconstruction images of the sample in the traditional bright field lighting and the bottle beam dark field,it is proved that the digital holography method based on the bottle beam lighting can effectively improve the resolution of the digital holographic microsystem and enhancethe contrast of the reconstructed image.