Electron volt energy resolution with ptychography using a broadband continuum spectrum

TL;DR

This paper investigates the energy resolution limits of ptychography with broadband spectra, demonstrating simulations and experiments that achieve sub-5 eV resolution in hard x-ray imaging, with implications for high-resolution diffraction techniques.

Contribution

It provides a theoretical and simulation-based analysis of energy resolution constraints in broadband ptychography and benchmarks these with experimental data, advancing the technique's capabilities.

Findings

Achieved 1 eV energy resolution in simulations.

Extracted x-ray absorption spectra with 5 eV resolution.

Provided guidelines for future broadband ptychography experiments.

Abstract

Ptychography is a scanning coherent diffraction imaging technique successfully applied in the electron, visible and x-ray regimes. One of the distinct features of ptychography with respect to other coherent diffraction techniques is its capability of dealing with partial spatial and temporal coherence via the reconstruction algorithm. Here we focus on the temporal and clarify theoretically and with simulations the constraints which affect the energy resolution limits of the ptychographic algorithms. Based on this, we design and perform simulations for a broadband ptychography in the hard x-ray regime, which enables an energy resolution down to 1 eV. We benchmark the simulations against experimental ptychographic data from a nickel test sample, by extracting the x-ray absorption near edge spectrum with energy resolution of 5 eV using a continuum spectrum of 20 eV bandwidth. We review the results, discuss the limitations, and provide guidelines for future broadband ptychography experiments, its prospective applications and potential impact on achieving diffraction limited resolutions.