Estimation of the tip field enhancement on a field emitter under laser illumination

We report the experimental evidence of controlled field evaporation of atoms from the surface of a tip-like-shape specimen with subwavelength dimensions by means of subpicosecond laser pulses. It is shown that the evaporation is assisted by the intrinsic laser electric field without any significant thermal activation. The single-atom detection sensitivity of the field ion microscope is used to get an accurate. measurement of the electric field enhancement factor at the tip apex as a function of the wave polarization. The absence of thermal diffusion of atoms at the tip surface prior to field evaporation, demonstrates the feasibility of a laser assisted three-dimensional atom probe. (C) 2005 American Institute of Physics.