A high-performance reconstruction method for partially coherent ptychography

TL;DR

This paper introduces a universal, high-tolerance reconstruction algorithm for ptychography that enhances image quality and convergence speed under low coherence conditions, applicable to both electron and X-ray microscopy.

Contribution

The proposed method is practical for partial coherence, requires no prior source knowledge, and improves existing ptychographic reconstructions by increasing stability and efficiency.

Findings

Significantly improves reconstruction quality in low coherence scenarios.

Accelerates convergence rate of ptychographic algorithms.

Compatible with existing ptychographic systems and enhances weakly scattering sample imaging.

Abstract

Ptychography is now integrated as a tool in mainstream microscopy allowing quantitative and high-resolution imaging capabilities over a wide field of view. However, its ultimate performance is inevitably limited by the available coherent flux when implemented using electrons or laboratory X-ray sources. We present a universal reconstruction algorithm with high tolerance to low coherence for both far-field and near-field ptychography. The approach is practical for partial temporal and spatial coherence and requires no prior knowledge of the source properties. Our initial visible-light and electron data show that the method can dramatically improve the reconstruction quality and accelerate the convergence rate of the reconstruction. The approach also integrates well into existing ptychographic engines. It can also improve mixed-state and numerical monochromatisation methods, requiring a smaller number of coherent modes or lower dimensionality of Krylov subspace while providing more stable and faster convergence. We propose that this approach could have significant impact on ptychography of weakly scattering samples.