Plasmon-mediated vectorial topological dipole: Formation and annihilation

Abstract

We report the formation and annihilation of vectorial topological dipole mediated by plasmons in structure-free metal surfaces using a polarization singular optical beam. The measured far-field behavior is due to the strong angular and polarization dependence of the reflection coefficient and the phase shift experienced by the spatially inhomogeneous polarized beam around the plasmon resonance. The threshold polarization ellipticity (σth) anticipated for the dipole formation is experimentally verified. © 2012 Optical Society of America.