title: Effects of missing low-frequency information on ptychographic and plane-wave coherent diffraction imaging.
abstract: In coherent diffractive imaging (CDI) experiments, a beamstop (BS) is commonly used to extend the exposure time of the charge-coupled detector and obtain high-angle diffraction signals. However, the negative effect of a large BS is also evident, causing low-frequency signals to be missed and making CDI reconstruction unstable or causing it to fail. We performed a systematic simulation investigation of the effects of BSs on the quality of reconstructed images from both plane-wave and ptychographic CDI (PCDI). For the same imaging quality, we found that ptychography can tolerate BSs that are at least 20 times larger than those for plane-wave CDI. For PCDI, a larger overlap ratio and a smaller illumination spot can significantly increase the imaging robustness to the negative influence of BSs. Our results provide guidelines for the usage of BSs in CDI, especially in PCDI experiments, which can help to further improve the spatial resolution of PCDI.
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, China.
authors.forename: Haigang
authors.initials: H
authors.lastname: Liu
authors.forename: Zijian
authors.initials: Z
authors.lastname: Xu
authors.forename: Xiangzhi
authors.initials: X
authors.lastname: Zhang
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Wu
authors.forename: Zhi
authors.initials: Z
authors.lastname: Guo
authors.forename: Renzhong
authors.initials: R
authors.lastname: Tai
mesh_terms: D000465:Algorithms; D016477:Artifacts; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007368:Interferometry / Q000379:methods*; D012031:Refractometry / Q000379:methods*; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity