Production of very high electron density assisted by lasers

An analysis is presented of a new basic concept for very-high-electron-density emission from metal photocathodes conjugating the action of two lasers. The action of the first laser, a low-frequency (infrared or far-infrared), high-density source (>10 to 100 MW/cm/sup 2/), is supported to lower the potential barrier and enhance the energy of conduction electrons at the surface of the material and increase significantly the effective photoelectric quantum yield. The second laser is a visible or ultraviolet laser with a lower intensity (<100 kW/cm/sup 2/), extracting a high electron density by direct photoelectric effect.<
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