Theoretical analysis of diffraction imaging in Fourier ptychography microscopy

摘要

Fourier ptychography microscopy (FPM) is a recently developed computational imaging approach which surpasses theresolution barrier of a low numerical aperture (NA) imaging system. It is a powerful tool due to its ability to achieve superresolution of complex sample function, pupil aberration, LED misalignment, and beyond. However, recent studies havefocused more on the optimization algorithms and set-ups instead of its theoretical background. Although some imaginglaws about FPM have already been set forth, the formulas and laws are not fully defined, and the connection betweendiffraction theory and Fourier optics has a gap. Therefore, there exist a need for comprehensive research on physical andmathematical basis of FPM for future applications. Keeping this goal in mind, this manuscript utilizes scalar fielddiffraction theory to rigorously study the relationship between wavelength, the propagation mode, illumination directionof the incident wave, sample structure information and the direction of the output wave. The theoretical analysis ofdiffraction imaging in FPM provides a clear physical basis for not only the FPM systems, but also for the ptychographyiterative engine (PIE) and any other coherent diffraction imaging techniques and systems. It can help to find the source ofnoise and therefore improve image quality in FPM technique and systems.