Practical Electron Microscopy and Database

Research and engineering applications of off-axis electron holography can be split into three main categories:
        i) Correct microscope aberration to achieve high spatial resolution,
        ii) Measure electric fields in materials at high spatial resolution,
        iii) Measure magnetic fields at high spatial resolution.

In the indirect aberration correction method with holography, this technique measures the exit wave function in the image plane, ψ_im(g), and then restore the exit wave in the object plane, ψ_obj(g), by applying a numerical phase-plate exp(-2πiχ(g)). The aberration function χ(g) is determined independently. [1, 2] The restored exit wave in the object plane can provide atomic structure information without delocalization and better information limit.

[1] Saxton, W.O. (1994). What is the focus variation method? Is it new? Is it direct? Ultramicroscopy 55, 171–181.
[2] Lehmann, M. (2000). Determination and correction of the coherent wave aberration from a single off-axis electron hologram by means of a genetic algorithm. Ultramicroscopy 85, 165–182.