27 research outputs found
Magnetic Phase Imaging using Lorentz Near-field Electron Ptychography
Over the past few years, the combination of diffuser and near-field electron
ptychography has drawn more attention by its ability to recover large field of
view with few diffraction patterns. In this paper, we purpose a novel design
and implementation of amplitude diffuser. The amplitude diffuser introduces
structures to the illumination while reducing the inelastic scattering. And the
amplitude diffuser is implemented at the condenser lens aperture, allowing us
to vary the illumination size under the same microscope setup. We demonstrate
the reconstruction results under both conventional Transmission Electron
Microscopy (TEM) mode as well as Lorentz mode.Comment: Presented in ISCS2
Efficient large field of view electron phase imaging using near-field electron ptychography with a diffuser
Most implementations of ptychography on the electron microscope operate in scanning transmission (STEM) mode, where a small focussed probe beam is rapidly scanned across the sample. In this paper we introduce a different approach based on near-field ptychography, where the focussed beam is replaced by a wide-field, structured illumination, realised through a purpose-designed etched Silicon Nitride window. We show that fields of view as large as 100 μm2 can be imaged using the new approach, and that quantitative electron phase images can be reconstructed from as few as nine near-field diffraction pattern measurements