New Type Femtosecond Streak Tube

The mechanism of intensity dependent recorded pulse broadening in the magnetic focusing femtosecond streak tube has been analyzed. The results have shown that it is due to broadening of an electron packet along the tube axis induced by space charge effects between the photocathode and the deflection electrode. Based on these analyses, a new tube with high dynamic range has been proposed. Photoelectron beam is swept by the deflection electrode immediately after it has been emitted from the photocathode. After passing the deflection electrode, the beam is focused by the focusing electron lens on the output screen. The temporal resolution of the tube is -500fs. Improved results are being obtained.