Efficient Synthetic Aperture for Phaseless Fourier Ptychographic Microscopy with Hybrid Coherent and Incoherent Illumination

Abstract Fourier ptychographic microscopy (FPM) is a computational high‐throughput technique for high‐resolution and wide field‐of‐view (FOV) imaging applications such as cell biology, medicine screening, and digital pathology. By integrating angle‐varied illumination, iteration phase retrieval, and synthetic aperture, it achieves a significantly enhanced imaging resolution beyond the diffraction limit of the objective lens while retaining its original large FOV without any mechanical movement. However, sufficient data redundancy is a prerequisite for the convergence of the iteration algorithm, which in turn requires dozens or even hundreds of raw images to get a decent resolution, leaving ample room for further improvement. In this paper, an efficient synthetic aperture scheme for FPM is proposed, termed ESA‐FPM. It employs both coherent and incoherent illuminations to maximize the efficiency of data utilization and achieve high spatial‐bandwidth product (SBP) reconstruction with few acquisitions. The data redundancy requirements are further analyzed, suggesting that ESA‐FPM reaches imaging resolution of using only seven images. The experiment with USAF target demonstrates that ESA‐FPM achieves theoretical resolution with only 1.6% of the data of conventional FPM. A customized miniaturized ESA‐FPM system with a high‐numerical‐aperture, low‐magnification objective lens, and a high‐brightness LED array is built, demonstrating its potential for biomedical and pathological applications.