A Label-free Super Resolution Optical Microscopy Based On Super Oscillation Lens

In recent years,constantly achieving optical imaging resolution beyond the diffraction limit has become a hot research area in optical fields.Since early 20 th century,Researchers have proposed various ways to realize optical superresolution microscopy.Along with the improvement of optical imaging resolution,super-resolution microscopy has been applied in various fields such as biomedicine,materials,chemistry,spectroscopy.However,common super-resolution microscopy techniques usually require fluorescent labeling which has a certain phototoxicity for biological samples.In this article we use an label-free super resolution optical microscope based on super oscillation lens which can effectively solve this problem with a good research perspective.The main work of this article includes:(1)Here we introduced the research background,research significance and research status of super-resolution microscopy technology,and proposed the research objectives and research content of this paper.(2)We introduced the related theory of point spread function and circularly polarized light,and deduced the circular polarized light vector angular spectrum propagation formula.(3)We briefly introduced the particle swarm optimization algorithm and used the particle swarm optimization algorithm combined with the circular polarization vector angular spectrum diffraction formula to design a lens with a radius of 650?,a focal length of 200?,a numerical aperture of 0.956,a FWHM of 0.379? which is smaller than the super-oscillation limit at the focal plane,a sidelobe ratio of 34.989%.(4)According to the basic working principle of the label-free super resolution optical microscope based on super oscillation lens,we built a super-resolution optical microscopy system and its front-end light path and completed the system control program,data processing program,and image reconstruction program,and finally briefly introduced the DLL,muti-thread controlling and the data processing method.(5)The experimental results showed that the FWHM in the focal plane of the super-oscillating lens based on the circular polarized light vector angular spectrum diffraction formula and the particle swarm algorithm is 0.381? on the X direction which breaks the super-oscillation limit,and 0.413? on the Y direction which breaks the diffraction limit of 0.523?,and it is very close to the super-oscillation limit.It's validate the feasibility and validity of the system.(6)Considering comprehensively,the ultra-long optical needle focused by the Fresnel zone plate was chosen for microscopic experiment which realizes a length of 88.263?,and the part that breaks the diffraction limit reaches 67.902?.(7)A focused beam spot with good symmetry and uniformity was selected as the scanning beam of the microscopy which was chosen from the ultra-long optical needle.Experimental results showed that our microscope achieve a resolution of ?/3.