Since the manufacture of the first commercial electron microscope in 1939, instrument developers have sought to improve resolution by designing ever-better electromagnetic lenses to steer and shape the electron beam. Resolution improvement of a factor of 70 (to 1.5 Ångström) was achieved in the first 40 years, but over the subsequent 2 - 3 decades resolution gains have been incremental, and achieved only at huge cost.
However, the best resolution obtained using conventional lens technologies (about 0.5Å) is still a factor of about 20 away from electron microscopy’s ultimate theoretical wavelength limited resolution.
The Phase Focus Virtual Lens® does not rely on conventional lens technology. Although Virtual Lens is, in principle, limited only by wavelength, a “mere” factor of two or three improvement in resolution beyond the current 0.5Å conventional lens-engineering limit would be transformational. The Phase Focus Virtual Lens® also offers the possibility of performing transmission electron microscopy on a scanning electron microscope in a “two-in-one” single instrument.
Electron phase microscopy is an inherent feature of the Electron Virtual Lens. Quantitative phase information is otherwise available only via the esoteric and technically challenging technique of electron holography. Electron applications enabled by the Electron Virtual Lens include:
- “Magnetic Microscopy” (visualisation and analysis of electro-magnetic phenomena such as the magnetic fields in superconductors or recording media);
- Analysis of electric fields in p-n junctions; specimen thickness; dislocations and strain fields; and inner potential in semiconductors
- Imaging of biological specimens (effectively transparent to electrons) without the need for damaging heavy metals stains.
