Double-biprism electron interferometry

Electron holography based on two electron biprisms was developed. The upper biprism was installed just on the image plane of the objective lens, and the lower one was set between the crossover point and image plane of the magnifying lens. This system was able to control two important parameters of the hologram-fringe space and width of interference region-independently. The system enabled us to perform electron holography and interferometry more flexibly. We confirmed the good performance of the system and did preliminary applications using a 1-MV field-emission electron microscope. (C) 2004 American Institute of Physics.