On the interaction of an ultra-fast laser with a nanometric tip by laser assisted atom probe tomography: A review

The evaporation mechanisms of surface atoms in laser assisted atom probe tomography (LA-APT) are reviewed with an emphasis on the changes in laser-matter interaction when the sample is a nanometric tip submitted to a high electric field. The nanometric dimensions induce light diffraction, the tip shape induces field enhancement and these effects together completely change the absorption properties of the sample from those of macroscopic bulk materials. Moreover, the high electric field applied to the sample during LA-APT analysis strongly modifies the surface optical properties of band gap materials, due to the band bending induced at the surface. All these effects are presented and studied in order to determine the physical mechanisms of atoms evaporation in LA-APT. Moreover, LA-APT is used as an original experimental setup to study: (a) the absorption of nanometric tips; (b) the contribution of the standing field to this laser energy absorption and (c) the heating and cooling process of nanometric sample after the interaction with ultra fast laser.