Enhancing Multi-Distance Phase Retrieval via Unequal Interval Measurements

Abstract

In the conventional methods of multi-distance phase retrieval, the diffraction intensity patterns are recorded at equal intervals, which can induce slow convergence or stagnation in the subsequent reconstruction process. To solve this problem, a measurement method with unequal intervals is proposed in this paper. The interval spacings between adjacent measurement planes are decreased gradually. A large gap accelerates retrieval progress, and a short span helps to recover detailed information. The proposed approach makes full use of the available measured dataset and simultaneously generates variations in diversity amplitude, which is a crucial issue for the techniques of multi-image phase retrieval. Both computational simulations and experiments are performed. The results demonstrate that this method can improve the convergence speed by 2 to 3 times and enhance the quality of reconstruction results in comparison to that of the conventional methods.

Resolution-Enhanced Ptychographic Modulation Imaging via Divergent Illumination

“…One strategy is to scan the detector axially along the optical axis and record the diffraction patterns over different locations. Through iterative diffraction calculations between the object plane and a series of measurement planes, the complex wavefront of the object can be retrieved without prior knowledge [8][9][10][11][12]. Ptychography imaging with spatially confined illumination is another strategy that captures hundreds of diffraction intensities by laterally moving the object with a localized probe beam at several grid positions [13,14].…”

Enhanced single-beam multiple-intensity reconstruction via unequal interval measurement and weighted feedback

“…To overcome this constraint, we introduce two enhancements to the SBMIR technique. The initial enhancement entails a reimagined approach to measurement [12]. Conventionally, diffraction intensities of samples are gathered at equidistant diffraction distances.…”