Approaching routine phase resolution for off-axis type holography

Off-axis type holography as introduced by Mِllenstedt for electron optics and by Leith et al. for light optics is based on the same principles. The general perception is that holography with light has a distinct advantage over electron holography simply because of the much higher brightness of the laser over any known electron source. However, light-optical elements introduce diffuse scattering within each optical element and back-reflection on each surface even in the most advanced optical systems. Thus light-optical phase resolution is limited by these parameters. Not so in electron optics where its optical elements introduce neither diffuse scattering nor back-reflections as the electron beam remains in vacuum. Thus the question what ultimately limits the phase resolution for off-axis electron holography apart from sample sensitivity to radiation damage is an important question to be asked.