Discrete Chromatic Aberrations Arising from Photoinduced Electron-Photon Interactions in Ultrafast Electron Microscopy

Dayne A. Plemmons, David J. Flannigan

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

In femtosecond ultrafast electron microscopy (UEM) experiments, the initial excitation period is composed of spatiotemporal overlap of the temporally commensurate pump photon pulse and probe photoelectron packet. Generation of evanescent near-fields at the nanostructure specimens produces a dispersion relation that enables coupling of the photons (= 2.4 eV, for example) and freely propagating electrons (200 keV, for example) in the near-field. Typically, this manifests as discrete peaks occurring at integer multiples (n) of the photon energy in the low-loss/gain region of electron-energy spectra (i.e., at 200 keV ± neV). Here, we examine the UEM imaging resolution implications of the strong inelastic near-field interactions between the photons employed in optical excitation and the probe photoelectrons. We find that the additional photoinduced energy dispersion occurring when swift electrons pass through intense evanescent near-fields results in a discrete chromatic aberration that limits the spatial resolving power to several angstroms during the excitation period.

Original languageEnglish (US)
Pages (from-to)3539-3546
Number of pages8
JournalJournal of Physical Chemistry A
Volume120
Issue number20
DOIs
StatePublished - May 26 2016

Bibliographical note

Funding Information:
This work was supported primarily by the National Science Foundation through the University of Minnesota MRSEC under Award Number DMR-1420013, in part by a 3M Nontenured Faculty Award under Award Number 13673369, and in part by the Arnold and Mabel Beckman Foundation through a Beckman Young Investigator Award. Acknowledgement is made to the Donors of the American Chemical Society Petroleum Research Fund for partial support of this research under Award Number 53116-DNI7. D.A.P. acknowledges support in the form of a Doctoral Dissertation Fellowship from the University of Minnesota Graduate College.

Publisher Copyright:
© 2016 American Chemical Society.

Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.

How much support was provided by MRSEC?

  • Primary

Reporting period for MRSEC

  • Period 3

PubMed: MeSH publication types

  • Journal Article

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