Direct acquisition of interferogram by stage scanning in electron interferometry.

We present an electron holography technique to acquire an interferogram, that is, cosine image of phase distribution. The interferogram is constructed by shifting the specimen in one direction with a stage-scanning system and acquiring line intensities of holograms. Taking line intensities eliminates the carrier fringes in the holograms and yields the interferogram. Under phase object approximation, the object phase can be readily obtained from the interferogram without any reconstruction procedure. The spatial resolution of phase is determined independently of the fringe spacing, overcoming the limitation of conventional techniques based on the Fourier transformation method.