Sensitivity, resolution (MTF) and signal to noise ratio are three fundamental performances of a image intensifier,
by which night system' detection range or image definition are mainly determined. On basis of photo-electronic
imaging theory, a series of analysis and assessment are carried out in the paper on the limit value of the three
performances. Under ideal specification conditions theoretical calculation results are given using several
expressions, which is ≤ 6569μA/lm of limit sensitivity, ≤ 96 lp/mm of limit resolution and ≤ 64 of limit signal to
noise ratio, respectively. These analysis method and results are useful as a strive goal and technical references
for those skilled in the art.
A design idea of extended blue NEA GaAs photocathode is given in this paper. A new structure is presented by changing the composition of GaAlAs in grads in order to get the short wavelength response and in the same time to reduce the stress in the photocathode material, so that an extended blue GaAs photocathode with a higher sensitivity of image intensifier can be obtained. Finally, the spectrum responses of both ordinary and extended blue GaAs image intensifier are given, the relationship of material structure and the result of blue extending is discussed.
The luminescence generation mechanism of semiconductor epitaxial structure and the basic principle of photoluminescence spectrum measuring instrument are outlined in this paper. Detailed method about how to make use of the instrument to measure the doping level and composition as well as the uniformity of GaAs/GaAlAs layer is described. In the end, the effect of these parameters on the function of the III-gen photocathode is discussed.