TY - JOUR
T1 - Prospects for quantitative and time-resolved double and continuous exposure off-axis electron holography
AU - Migunov, Vadim
AU - Dwyer, Christian
AU - Boothroyd, Chris B.
AU - Pozzi, Giulio
AU - Dunin-Borkowski, Rafal E.
N1 - Funding Information:
We acknowledge Christophe Gatel and Etienne Snoeck from CEMES-CNRS in Toulouse for drawing our attention to the possibilities of high frequency double exposure off-axis electron holography. We are grateful to Michael Farle and AG Farle at the University of Duisburg-Essen for technical help, Enrico Nichelatti for valuable discussions and the European Union Seventh Framework Programme for funding under Grant Agreement 312483-ESTEEM2 (Integrated Infrastructure Initiative-I3). The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ ERC grant agreement number 320832.
Publisher Copyright:
© 2016 The Authors
PY - 2017/7/1
Y1 - 2017/7/1
N2 - The technique of double exposure electron holography, which is based on the superposition of two off-axis electron holograms, was originally introduced before the availability of digital image processing to allow differences between electron-optical phases encoded in two electron holograms to be visualised directly without the need for holographic reconstruction. Here, we review the original method and show how it can now be extended to permit quantitative studies of phase shifts that oscillate in time. We begin with a description of the theory of off-axis electron hologram formation for a time-dependent electron wave that results from the excitation of a specimen using an external stimulus with a square, sinusoidal, triangular or other temporal dependence. We refer to the more general method as continuous exposure electron holography, present preliminary experimental measurements and discuss how the technique can be used to image electrostatic potentials and magnetic fields during high frequency switching experiments.
AB - The technique of double exposure electron holography, which is based on the superposition of two off-axis electron holograms, was originally introduced before the availability of digital image processing to allow differences between electron-optical phases encoded in two electron holograms to be visualised directly without the need for holographic reconstruction. Here, we review the original method and show how it can now be extended to permit quantitative studies of phase shifts that oscillate in time. We begin with a description of the theory of off-axis electron hologram formation for a time-dependent electron wave that results from the excitation of a specimen using an external stimulus with a square, sinusoidal, triangular or other temporal dependence. We refer to the more general method as continuous exposure electron holography, present preliminary experimental measurements and discuss how the technique can be used to image electrostatic potentials and magnetic fields during high frequency switching experiments.
KW - Continuous exposure electron holography
KW - Double exposure electron holography
KW - Off-axis electron holography
KW - Transmission electron microscopy
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U2 - 10.1016/j.ultramic.2016.08.010
DO - 10.1016/j.ultramic.2016.08.010
M3 - Article
C2 - 27638333
AN - SCOPUS:84994888180
SN - 0304-3991
VL - 178
SP - 48
EP - 61
JO - Ultramicroscopy
JF - Ultramicroscopy
ER -