Otto Ernst Heinrich Klemperer (1899-1987) was a physicist expert in electron optics.
Some major parts of the guns' electron optics were common to all three beams, hence the name.
With today's electron optics, electron beam widths can routinely go down to a few nm.
How can we leverage the nanometer focusing ability of electron optics in optical microscopy of living specimens?
The electron optics of camera tubes differ considerably.
He held 19 patents for his inventions, and had more than 275 publications, most of them concerned with electron optics and electron microscopes.
Using a technical term borrowed from electron optics we could say that the electron beam gets defocused.
He received his doctorate in theoretical physics in 1950 by writing a dissertation about electron optics.
In electron optics, scanning electron microscopes use narrow pencil beams to achieve a deep depth of field.
There, he did research on electron optics.