Polarization dependence of the optical absorption of a subwavelength tip

Laser assisted atom probe tomography is used to investigate the polarization dependence of the absorption of a subwavelength tip illuminated by an ultra short laser pulse. Al and Si tips are investigated and experimental results are discussed and explained using electromagnetic theory in the simplified cylindrical geometry. Numerical simulations in a more real geometry are also presented and used to show limits of the cylindrical model and to show the role of the very end tip apex in the absorption process.

► We investigate the polarization dependence of the absorption of a subwavelength tip illuminated by an ultra short laser pulse. ► Different behaviors are reported on metallic (Al) and semi conducting (Si) tips. ► The experimental results are discussed and explained using electromagnetic theory in the simplified cylindrical geometry. ► Numerical simulations in a more real geometry are also presented. ► The limits of the cylindrical model are shown.