CHROMATIC COHERENCE AND INELASTIC-SCATTERING IN ELECTRON HOLOGRAPHY

The expectation that the coherent interference effects in off-axis electron holography may have the effect of removing contributions to the image from inelastically scattered electrons is valid only to the extent that the incident wave may be assumed to be monochromatic. A consideration of the coherence function in space and time and a simple treatment for time-dependent wave functions and object transmission functions both suggest that coherent diffraction effects and contributions to the holographically reconstructured image occur for inelastic scattering with energy losses comparable with the energy spread of the incident beams.