Conclusions

Abstract

Electron holography was invented by D. Gabor in 1948, but new applications of electron holography have only recently been opened up by making the best use of coherent beams from both a laser and a field-emission electron beam. Holography faithfully transforms electron wave fronts into optical wave fronts, enabling versatile optical techniques to become applicable to electron optics. The original objective of holography was to break through the resolution limit of electron microscopes by compensating, in the optical reconstruction stage, for the spherical aberration of the electron lens. Attempts have been made to actually achieve this objective, thus increasing the levels of technology to where we are on the brink of improving the resolution and making new discoveries.