题目：Phase retrieval algorithms and ptychography ，Non-iterative diffraction imaging method using partially coherent illumination
主讲人：荷兰Delft大学Sander Konijnenberg博士、邵屹峰博士
邀请人：王海凤教授
时间：2017年1月16日（周一）上午9:30
地点：图文信息中心第二会议室
内容简介：
（1）Phase retrieval algorithms and ptychography ：Coherent diffractive imaging (CDI) is a technique that can be used to image a sample without having to use lenses. Especially for X-ray imaging this may be useful, since the reconstructed image will not suffer due to low-quality focusing optics. One way of performing CDI is by using iterative phase retrieval algorithms. One such algorithm is ptychography, in which the probe that illuminates the sample is shifted to different positions, and for each position a far-field diffraction pattern is recorded. In this talk we will briefly discuss some iterative phase retrieval algorithms, with a special focus on ptychography.
（2）Non-iterative diffraction imaging method using partially coherent illumination：Coherent diffraction imaging (CDI) has particular importance for wavelengths at which no high quality and low price optical components are available, e.g. in the X-ray regime. In CDI one tries to reconstruct a complex-valued object from diffracted far field intensities. CDI requires complete coherent illumination of the object. However, current X-ray sources can only provide limited degree of coherence. Modifications of CDI using partially coherent illumination have been reported only for iterative methods and can adapt only limited deviation from the coherent illumination. In this talk, we will discuss the non-iterative approaches for diffraction imaging using partially coherent illumination. These approachescan reconstruct a complex-valued object when the coherence properties of the illumination is not known and can also determine the mutual coherence function of the illumination.
主讲人简介：
（1）Sander Konijnenberg博士:Sander Konijnenberg was born and raised in the Netherlands. He obtained his BSc in Applied Physics and Applied Mathematics, as well as his MSc in Applied Physics in Delft. Currently he’s in the beginning of his second year of his PhD in the Delft Optics Research Group.
（2）邵屹峰博士：Yifeng Shao was born in China. He graduated in 2011 at Sun Yat-sen University in China. He obtained two master degrees from the Erasmus Mundus master programme, one at the Institut d'Optique Graduate School in France and the other at the Delft University Technology in the Netherlands. Currently, he is a PhD student in the Optics research group at Delft University of Technology.