Figure 2: Simulations of the single QE–CPP mode coupling.

(a) Characterization of the coupling between a bare dipolar emitter and the VG-supported CPP mode. The dipole is placed in the centre of the VG and displaced along the vertical z axis. The shaded region represents the ND, which will be considered inside the VG later on. The Purcell factors for the three orthogonal dipole orientations are displayed with a colour code corresponding to that used in the inset. The black line shows the β-factor for a dipole oriented along the x axis for which the Purcell factor is enhanced. The β-factor is found to be close to zero for y and z orientations (not shown). (b) Normalized electric field maps for three different transversal cuts of the VG. The electric field profile resembles that of the VG-supported CPP mode already at 1.25 μm away from the QE (dipole oriented along the x axis). The colour scale has been adjusted in each panel for a better view. (c) Same quantities as in (a), when the dipolar source is located inside a 60-nm-radius ND sphere lying inside the VG. The β-factor and Purcell factor reach values of 0.56 and 5.2, respectively.