This proposal investigates the photon-statistics of light emitted by a statistical ensemble of cold atoms excited by the near-field of an optical nanofiber tip. Dipole-dipole interactions of atoms at such short distance from each other suppress the simultaneous emission of more than one photon and lead to antibunching of photons. We consider a mean atom number on the order of one and deal with a Poissonian mixture of one and two atoms including dipole-dipole interactions and collective decay. Time tracks of the atomic states are simulated in quantum Monte Carlo simulations from which the g (2) -photon autocorrelation function is derived. The general results can be applied to any statistical ensemble of emitters that are interacting by dipole-dipole interactions.

This paper reports on the excitation of surface plasmons on gold-coated nanofiber tips by side illumination with a laser beam and the coupling of the surface plasmons to the optical fiber. The measurements show a strong dependence of the coupling efficiency on the incidence angle with a maximum coupling efficiency on the order of a few percent. Moreover, the fiber tip was used as a scanning probe device for measuring the beam waist of a focused laser beam. This work is motivated by the goal to use such plasmonic nanofiber tips in quantum optics experiments with cold atoms.