Recent developments in electron holography for phase microscopy.

This paper reports on the recent remarkable progress made in electron phase microscopy, especially due to the development of both a "coherent" field-emission electron beam and the related image processing techniques. With these techniques, the phase distribution of an electron beam transmitted through a specimen can now be measured with a precision of within 1/100 of the electron wavelength to observe the thickness distribution of a uniform specimen at the atomic level, the magnetic domain structures in a ferromagnetic thin film, and individual vortices in a superconducting thin film. Vortices in superconducting thin films have become dynamically observable by Lorentz microscopy.