Visibility spectroscopy with electron waves using a Wien filter: higher order corrections

Fourier spectroscopy, one of the most precise spectrometry methods in light optics, has been realized in the past years with electron waves by including a crossed-field analyzer (Wien filter) as a wave packet shifting device into a biprism interferometer. To fully exploit the high precision of this method of determining the energy spectrum, higher order corrections stemming from the Wien filter's focusing action are necessary in the evaluation of the measurement. We show that these can be taken into account by using a transformation variable being proportional to the quotient of electric field strength of the Wien capacitor over fringe spacing. Finally, we make some remarks about the possibility of interference of inelastically scattered electrons.