Video-rate electron-holographic interference microscopy and its application to dynamic observation of electromagnetic fields

The system described here provides video-rate observation by using a liquid-crystal spatial light modulator as a rewritable electron-hologram medium. Time-sequential interference micrographs are produced by superimposing a plane reference wave on the object wave reconstructed from the hologram displayed on the modulator. Experimental observations of the magnetic field of a barium ferrite particle and of dynamic domain-wall motion in a thin ferromagnetic film are shown. The sources of error in system are discussed, and a distortion-free system is proposed.