Research On Superresolution Of Digital Holographic Microscopy With Phase Structured Light

The amplitude and phase distribution of the image light field are equally important factors in the measurement of micro digital holography.Since the current coherent imaging theory can only approximate the amplitude distribution of the image light field,the microscopic imaging system can only be regarded as a linear space invariant system for measurement and research.At the same time,in order to improve the imaging resolution of the image field,the "optical frequency shift superresolution imaging method" using structured light illumination has achieved many excellent research results,which can make the amplitude resolution of the reconstructed image higher than the Rayleigh resolution limit.Structured light illuminated digital holographic microscopy(SI-DHM)is a fast and wide-field detection technique that does not require marking and staining of the measured object.In biomedical applications,it can also be used in materials science,micro-nano circuit imaging and many other fields to achieve super-resolution detection.This paper focuses on the precise calculation theory of coherent light imaging system and the digital holographic microscopic super resolution system for phase structured light illumination,and completes the following research work:Firstly,the classification and corresponding recording principles and reproduction methods of digital holography are introduced.Based on the image surface information structure,the separation conditions of reconstructed images of off-axis digital holography are analyzed,and three commonly used digital reproduction algorithms are summarized,and the principles and characteristics of each algorithm are analyzed.Then,according to the approximate coherent imaging formula,the method of calculating the amplitude and phase information of the image plane is introduced.Based on this,the theoretical formula which can accurately calculate the amplitude and phase distribution of the image light field is proposed.The correctness and practicability of the improved accurate calculation theory are verified by the simulation and optical experiments of single lens coherent imaging and digital holography.Finally,the method of using oblique light to form phase structured light and using multi-angle spectrum synthesis to achieve super resolution is discussed.The principle of SI-DHM resolution enhancement is verified by numerical simulation experiments.By optimizing different simulation parameters,the precise calculation of amplitude and phase super resolution distribution is realized.The conditions for improving the resolution without distortion of SI-DHM are discussed.This method provides a useful reference for the application of microscopic superresolution imaging.