A software package for the processing and reconstruction of electron holograms

Abstract

SUMMARY Electron holography is leaving its state of infancy and is rapidly becoming a tool for everyday use. This is due to the increasing availability of field‐emission electron microscopes as well as the increasing use of slow‐scan CCD cameras, which provide the linear image recording so essential to electron holography. At the same time, the continuing boost in performance of desktop computers both in hardware and in software has facilitated the handling of many of the complex reconstruction and processing tasks of electron holography. We describe here the software package ‘HoloWorks©’, recently developed at Oak Ridge National Laboratories. This package is designed for the processing of electron holograms stressing easy‐to‐use functions and is a plug‐in module for Gatan's software DigitalMicrograph®.

Off-Axis Electron Holography of Magnetic Nanostructures: Magnetic Behavior of Mn Rich Nanoprecipitates in (Mn,Ga)As System

“…In this paper, four holograms for the same region of the sample are analyzed: one for the upside and one for the downside configuration at RT of 296 K and analogous holograms for liquid nitrogen temperature (LNT) of 120 K. [21]. Figure 2 shows the electrostatic and the magnetic phases determined from the upside/downside method.…”

“…All images were recorded on a 2048 × 2048 pixel CCD camera. The off-axis holograms were reconstructed by means of Holo3 [21] and HolograFree [22] software. The reconstructed phases were exploited to extract the electrostatic and magnetic contributions to the phase shift.…”

Semiconductor wafer defect detection using digital holography

“…This is shown in Figure 5 below. In this case, the phase image has been corrected using the reconstructed image of a flat surface in the object arm [7,8]. This technique corrects for any curvature present in the object wave that is not caused by the object itself.…”

“…The information contained in the sideband around this carrier frequency is the (resolution-limited) complex wavefront information. By extracting one of the two sidebands from the Fourier transform, applying a digital lowpass filter to remove any unwanted contribution from the autocorrelation band or possible aliased frequencies (see Figure 4), and computing the inverse Fourier transform, the complex wavefront from the target arm is reproduced in digital form [6][7][8][9]. This digital reproduction is, of course, subject to the distortions introduced to it by the optical imaging system and also by computational and quantization error.…”

Magnetization of carbon-coated ferromagnetic nanoclusters determined by electron holography

“…The following simulations will substantiate all three claims. The simulations were carried out by Mathematica and HoloWorks 19 software. Mathematica was used to stimulate the phase maps which were subsequently used to calculate with HoloWorks a set of holograms with different spatial-resolution values.…”