Practical Electron Microscopy and Database

The wave function of the focused probes in STEM and SEM is given by, [1,2]

          -------------------------[2580]

where,
         γ(K) -- The aberration function in radians (i.e., the phase difference between the aberrated wavefront and the ideal wavefront).

In Equation 2580, the integration represents coherent sum over all contributions of waves passing through the probe-forming lens aperture. The first exponential term gives the relative path difference of different waves, while the second exponential term presents the overall aberration of the probe-forming electro-optical system.

[1] Hartel P. Ultramicroscopy 1996;63:93–114.
[2] Kirkland EJ, Loane RF, Silcox J. Ultramicroscopy 1987;23:77–96.