Generate localized optical vortices by quadrupole transition and twisted light

Abstract

We explain how quadrupole-active atomic interactions be able to be enhanced once the neutral atom interacts with an evanescent winding light modes. The optical system presented is a semi-bounded space based on neutral atoms situated close to the evanescent Bessel-Gaussian modes. The quadrupole Rabi frequency (and hence the optical quadrupole potential) generated by such evanescent modes is large enough to be exploited in atoms manipulation. In particular, the atomic states in which the dipole transitions are prohibited but the quadrupole transitions are permissible create the optical quadrupole potential of accessible value to play an important role. It is also shown how such optical system acts to create of evanescent modes with having an orbital angular momentum in which the intensity distribution is restricted in the vicinity of the dielectric surface.