Imaging Research Of Far-field Optical Super-Resolution Microscopy Based On Structured Illumination

As an important tool to explore and research the microscopic world,optical microscope has many advantages such as non-contact,widely observable regions,realtime and directly imaging.With the developments of micro-nano manufacturing technology and the biological macromolecules researches,the measurement requirements have gradually shifted from the micron scale to the nanometer scale.However,due to the fluctuation of light and the impossibilities of infinite aperture in reality,there will always be some large-angle diffraction light lost in the imaging process,resulting that the image cannot completely restore all the information of the measured object.Therefore,the resolution of optical microscope has a diffraction limit,and the super-resolution techniques are invented for this problem.Among the existing super-resolution technologies,structured illumination technology is the best method of retaining almost all the advantages of optical microscope,but it needs to reconstruct the collected high-frequency details using phase shifts of illumination.However,the phase shift method needs the support of precision equipment and spends too much time,which is not conducive to a long-term development.Based on this background,this paper proposes a meaningful reconstruction method without phase shift.The main contents are as follows:1.In order to study the cause of diffraction limit,the imaging process of highfrequency details was analyzed based on diffraction theory,which obtains the deep principle of super-resolution using structured illumination;2.In order to solve the inherent problems of the phase shift method,a reconstruction method was proposed.For higher resolution,we analyzed the relationship between the frequency of illumination and the maximum resolution.The resolution of imaging system using proposed method could achieve more than double enhancement through a suture of spectra,which is superior to traditional phase shift method and various super-resolution methods.3.In order to verify the feasibility of the proposed method,two numerical simulations were designed.The results showed that the proposed method had unique advantages in the maximum resolution,reconstruction speed,low requirements of parameters precision,multi-directional expansion,good imaging quality and other aspects.4.According to the current measurement requirements,a reflective microscopic imaging system based on the proposed method was developed,and the super-resolution imaging of standard resolution chart was successfully realized.