<title>New approach to elimination of the perturbing effect of long-range electromagnetic fields in electron holography</title>

Abstract

It is a general problem in the electron holography that the long-range fields always affect the phase of the reference wave. The electromagnetic field of the specimen, which always spreads outside the specimen, not only is strictly limited within the region crossed by the object wave, but also extends as far as the region crossed by the reference wave, so the phase of the reference wave becomes unknown as well as that of the object wave. The perturbation of the reference wave has far-reaching consequences that a reliable reconstruction of the original object wave is presented since an optical replica of the perturbed reference wave is not available. In this paper, we proposed a method to eliminate the influence of the perturbed reference wave. Based on phases' relationship between the reference wave and the object wave, with digital reconstruction and data process, we can extract the phase of object wave from the phase difference between the object wave and the perturbed wave, which is always obtained in normal reconstruction. An example of one-dimension electromagnetic fields is given to verify this method.