LASER CLEANING OF FIELD EMITTER ARRAYS FOR ENHANCED ELECTRON-EMISSION

The effect of laser irradiation on the electron emission efficiency of field emitter arrays has been investigated as a function of wavelengt h using different harmonics of a diode-pumped Nd:YLF laser. While irra diation in the infrared or visible range did not induce any observable change in the emission behavior, ultraviolet laser irradiation, even at a lower fluence compared to infrared or visible, resulted in a sign ificant increase of the emission efficiency, revealing that the photod ecomposition of organic contaminants is the main mechanism for cleanin g. During laser irradiation, the emission current increases gradually, approaching a saturation level as the surface is cleaned. (C) 1998 Am erican Institute of Physics.