Single-shot Fourier ptychography using polarization-encoded illumination

Abstract

Fourier ptychography (FP) is widely adopted for label-free, high-resolution quantitative phase imaging (QPI) of biological samples. However, its imaging speed is limited by the need for multiple acquisitions. In this work, we propose a single-shot FP technique that uses linear polarizers to encode multiple illumination wavevectors and a polarization camera to capture multiple sets of information simultaneously. A multiplexed FP algorithm, utilizing both the bright-field and dark-field information, reconstructs a high-resolution quantitative phase image from the single-shot intensity image. Verified with resolution targets and a histological sample, our method achieved a resolution improvement of 2.5 times the diffraction limit of the objective lens and provided QPI over a large field-of-view. Additionally, we demonstrated high-speed FP at 75 frames per second, limited only by the sensor's readout speed, enabling QPI of fast-moving microorganisms.