Reconstruction of Wigner function of electron beams based on coherence measurements

TL;DR

This paper presents a novel method to reconstruct the Wigner function of electron beams from coherence measurements, enabling more accurate assessment of emitter performance in electron microscopy.

Contribution

The authors developed a new reconstruction technique for the electron beam's Wigner function and density matrix using coherence analysis, improving emitter brightness evaluation.

Findings

Successfully reconstructed the Wigner function from experimental data

Derived a formula for axial brightness based on the Wigner function

Achieved more precise emitter performance measurements

Abstract

We developed a reconstruction method for the density matrix and Wigner function of electron beams through analysis of the Airy pattern intensity profile. The density matrix in a transmission electron microscope object plane was calculated using the coherence function and the electron wave amplitude and phase distributions. The Wigner function was then reconstructed using the matrix elements. Based on the Wigner function at the origin of the phase space, we derived a formula to calculate the axial brightness, and then determined the axial brightness of a Schottky field emission gun, which reflects the emitter performance more accurately and precisely than the conventional mean brightness measurements.