ELECTRON HOLOGRAPHY

This is an image of a fluxon in Niobium. The black contours represent the magnetic lines of force in this superconductor. Magnetic fields may be visualized by means of electron holography whereby the phase of an electron wave can be reconstructed. These reconstructions were part of a project at Hitachi's Advanced Research Laboratory in Japan with Dr. Akira Tonomura.

Holography can be used to measure and observe a wide variety of electro magnetic phenomena such as the magnetic fields in superconductors or recording media, the electric fields in pn junctions, specimen thickness, mean inner potentials of materials, dislocations, strain fields, electron microscope lens aberrations and much, much more.

Please view more examples of electron holography.

I have written some reconstruction routines for electron holography. I call it HolograFREE. The latest version is 3.5, you may download versions for Macintosh and MS Windows. I started the work at Lawrence Berkeley Laboratory and continue to improve the functionality all the time, please feel free to send suggestions :-). The routines are freeware, all you need is a field emission electron microscope and Gatan's DigitalMicrograph(TM) image processing package. I have no financial interest in Gatan...I just think it's a great app!