Concept, developments, and applications of ptychography

Due to the limitations of resolution, phase loss and the difficulty in imaging complex samples in traditional optical imaging techniques, problems such as poor imaging effect and slow imaging rate have occurred, thus ptychography is proposed. Ptychography is a high-resolution phase recovery method based on coherent diffraction imaging. This technology breaks through the limitation of the optical resolution of traditional microscopes. By scanning the sample and recording the diffraction patterns of the overlapping areas, combined with advanced phase recovery algorithms, it achieves high-precision reconstruction of the sample structure. Since Hoppe proposed the theoretical concept of ptychography in 1969, this technology has undergone multiple stages of development. In recent years, with the development of synchrotron radiation technology and the improvement of light source coherence, ptychography technology has developed rapidly. This paper systematically reviews the origin and core principles of ptychography, including its models, iterative algorithms for phase recovery, optimization methods such as error correction, and applications in multiple fields. In the future, ptychography will further shift from laboratory research to industrial-grade online detection and clinical diagnosis, providing an irreplaceable technical solution for further addressing the diffraction limit problem of traditional imaging.