Figure 2.

Sample fabrication and optical properties of SiV^– in parabolic reflectors (PRs). (a) Sample preparation workflow. First, we implant the diamond with ²⁹Si⁺ at a dose of 6 × 10⁹ ions/cm² at an angle of 7° and an energy of 80 keV. Then we anneal the diamond in a home-built high vacuum oven to produce SiV^–. Third, we nanofabricate parabolic reflectors and subsequently repeat the annealing procedure from step 2 to further increase the yield of SiV^– formation and to enhance optical coherence.²⁴ Gray dots are Si ions while red dots indicate successfully formed SiV^–. (b) SEM image of a PR array (imaging angle 70°). Binary bulk markers on the sample are visible to the left. (c) Example of a room-temperature (RT) background corrected off-resonant g⁽²⁾(τ) recorded on a PR by exciting the emitter with a 515 nm diode laser and recording the ZPL photoluminescence (PL) intensity. The fit (dashed yellow) to the data (gray) reveals g⁽²⁾(0) = 0.00 ± 0.16, indicating a single emitter. (d) SiV^– number distribution and a corresponding Poissonian fit with mean n̅ = 0.53 emitters per pillar. (e) Left panel: low-temperature (LT) resonant saturation curve on transition C recorded by tuning a diode laser into resonance and varying its optical power using an AOM while collecting PSB photons. Saturation power for this particular SiV^– is 23.0 ± 3.1 nW. Right panel: LT ZPL PL decay of the SiV^– recorded with off-resonant pulsed excitation at 515 nm. Fitting (yellow line) reveals a typical optical lifetime of 1.69 ± 0.04 ns.