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 wavelength using different harmonics of a diode-pumped Nd:YLF laser. While irradiation 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 significant increase of the emission efficiency, revealing that the photodecomposition of organic contaminants is the main mechanism for cleaning. During laser irradiation, the emission current increases gradually, approaching a saturation level as the surface is cleaned.