Accurate measurement of phase shift in electron holography

A method is proposed for the accurate measurement of phase shift in electron holography. The method is based on the use of moire fringes resulting from the subtraction of a null electron hologram by a real object hologram recorded under slightly different experimental conditions. This method does not require any optical or digital reconstruction of the electron hologram, and is shown to be highly sensitive to the phase shift of the electron wave passing through an object. Using experimental results obtained from a single particle of silicon, we demonstrate that the sensitivity of this method to phase shift may easily be amplified by more than 11 times compared with the conventional method using an ordinary electron hologram. (C) 1998 American Institute of Physics.