Nuclear Techniques ›› 2016, Vol. 39 ›› Issue (11): 110102-110102.doi: 10.11889/j.0253-3219.2016.hjs.39.110102

• SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS • Previous Articles     Next Articles

Improving the reconstructed image quality in ptychography using mixed states decomposition iterative phase retrieval algorithms

WANG Chunpeng1,2, XU Zijian1, TAO Xulei1,2, TAI Renzhong1   

  1. 1 Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jiading Campus, Shanghai 201800, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2016-08-26 Revised:2016-09-29 Online:2016-11-10 Published:2016-11-12
  • Supported by:

    Supported by the Ministry of Science and Technology of China (No.2012CB825705), National Natural Science Foundation of China (No.11225527, No.11575283, No.11505277)

Abstract:

Background: In most commonly used iterative phase retrieval algorithms in X-ray ptychography, the incident X-ray is considered to be fully coherent and monochromatic (i.e. in single state), the sample is considered to be stable or unchanged, and the responses of all optical elements in the system are considered to be fixed throughout the data acquisition process. However, in actual experiments, the above three conditions cannot be guaranteed simultaneously. Under non-ideal conditions, decoherence effects from single state changing or states mixture could severely deteriorate the reconstructed image quality. Purpose: This study aims to improve the reconstructed image quality using mixed states decomposition iterative phase retrieval algorithms to eliminate the negative influences of various types of decoherence effects. Methods: Two mixed state decomposition algorithms, the multi-mode extended ptychographical iterative engine (Mm-ePIE) algorithm and the sub-pixel up-sampling extended ptychographical iterative engine (Us-ePIE) algorithm are used to reconstruct the sample function and the probe function(s) simultaneously. Results: The results show that the decomposition effect of state mixture from different sources is embodied in both the reconstructed sample function and probe function(s). Conclusion: These two mixed-state decomposition phase retrieval algorithms can both improve the quality of the reconstructed image significantly. Moreover, the multi-mode algorithm performs better than the up-sampling algorithm in removing the decoherence effects.

Key words: X-ray ptychography, Mixed state, X-ray microscopy, Iterative phase retrieval algorithm

CLC Number: 

  • TL99