Fourier Ptychography for Brightfield, Phase, Darkfield, Reflective, Multi-Slice, and Fluorescence Imaging

Fourier ptychography (FP) is a recently developed computational framework for high-resolution multimodal imaging. In a coherent imaging setting, FP illuminates the sample with angle-varied plane waves and captures the corresponding intensity images. The captured intensity data are then iteratively synthesized in the Fourier space to recover a widefield, high-resolution complex sample image that bypasses the frequency limit of the employed objective lens. The recovery process of FP can also be extended to incoherent imaging settings where non-uniform intensity patterns are projected on the sample and the captured data are used for image reconstruction. In this paper, we will review the progress of the FP technique and discuss different implementations including LED-array illumination, liquid-crystal-display modulation, aperture-scanning approach, lensless synthetic aperture implementation, and incoherent-imaging implementation. We will also review different imaging modalities using FP and report the new developments of darkfield and epi-illuminated imaging modalities.