Ultrafast electron emission from metallic nanotip arrays induced by near infrared femtosecond laser pulses

The authors explore the impact of femtosecond light pulses on the field-emission properties of single-gate molybdenum field-emitter arrays with nanometer scale tip apex. Despite the small fraction of the emission area, we observed a single-photon photoelectric current from the emitter tips on top of the dc field-emission current under the irradiation of 50 fs laser pulses at a wavelength of 800 nm with an external quantum efficiency up to similar to 2 x 10(-7) and the emitter tip quantum efficiency of similar to 10(-2). The result indicates that metallic field-emitter arrays are promising for applications that require high-brightness short electron beams. (C) 2008 American Institute of Physics.