Figure 1

(a) Schematic of device concept (top) and scanning electron microscopy image using an Inlens detector (bottom) of the DBR resonator fabricated around a silver NW. The sample is tilted at 30° to demonstrate that the NW is suspended from the substrate in PMMA. $\mathrm{\text{Scale bar}}=1\mu \mathrm{m}$. (b) Simulated electric field intensity of a plasmonic cavity at wavelengths inside the stop band (top left), outside the stop band (bottom left), and on resonance (right). (c) Simulated transmission spectrum of a DBR consisting of a 100 nm silver NW and PMMA slabs with a period of 200 nm. A quarter-wave stack composed of 6 PMMA slabs reflects the incoming SPPs with a reflectivity exceeding 90%. (d) Simulated transmission spectrum of plasmon cavity composed of two DBRs. The nominal cavity length corresponds to ${\lambda }_{\mathrm{SPP}}$, and the linewidth gives a $Q$ of 100.Reuse & Permissions

Figure 2

(a) CCD image of SPP propagation overlaid on a scanning electron microscopy image of a device. (b) Transmission spectrum of plasmonic DBR. The minimum intensity in the stop band indicates a reflectivity of 90%–95%, and sideband oscillations can be seen outside the stop band. (c) Transmission spectrum of plasmon resonator. The peak in the stop band at 638 nm has a width of 11 nm, corresponding to a $Q$ of 58. Scanning electron microscopy images of both devices are shown in the insets, with scale bars that correspond to $1\mu \mathrm{m}$.Reuse & Permissions

Figure 3

(a) Fluorescence spectrum of CdSe quantum dots in the substrate (blue, dashed line) and coupled to the plasmon resonator (red line). The transmission spectrum of the device is overlaid (gray line, crosses). The fluorescence of coupled quantum dots is shifted and narrowed by the cavity resonance. (b) Lifetime measurements obtained by excitation with a pulsed laser of coupled (red line) and uncoupled (blue, dashed line) quantum dots. Uncoupled quantum dots have a lifetime of 16 ns, while coupled quantum dots show multiexponential behavior, with the initial slope corresponding to a lifetime of less than 250 ps.Reuse & Permissions

Figure 4

(a) Scanning confocal microscope images of the device. The top panel shows an image of the reflected green laser light. The middle panel shows fluorescence in the red as the laser is scanned over the area. When the laser is focused onto the NV in the cavity (indicated with a white circle), an independent collection channel is scanned over the area to detect fluorescence (bottom). The bright spot in the center results from direct excitation and detection of the NV fluorescence. Two additional spots can be seen from the ends of the wire, where SPPs excited by the NV scatter into free space. $\mathrm{\text{Scale bar}}=1\mu \mathrm{m}$. (b) The fluorescence spectrum from the center of the NW shows broadband emission characteristic of NVs. The inset shows autocorrelation of the fluorescence, which is strongly antibunched, indicating that emission results from a single NV center. (c) The fluorescence spectrum from the end of the NW (red line) shows significant modification, which corresponds to the transmission spectrum of the device (black line). Cross correlation between the SPP-coupled emission and the emission collected directly from the NV indicates that the fluorescence at the end of the NW originates from the same NV center (inset).Reuse & Permissions