Opt Lett. 2018 Nov 15;43(22):5587-5590. doi: 10.1364/OL.43.005587.
Precise detection of surface plasmons is crucial for the research of nanophotonics and quantum optics. In this Letter, we used a single nitrogen vacancy center in diamond as a probe to detect the surface plasmon that was tuned by the thickness of a metallic film. The fluorescence intensity and lifetime of the nitrogen vacancy (NV) center were measured to obtain the information of local light-matter interaction. A nonlinear thickness dependent change of the surface plasmon was observed, with the maximum at the thickness of approximately 30 nm. With optimized thickness of silver film, the fluorescence intensity of a single NV center was enhanced 2.6 times, and the lifetime was reduced by a factor of 3, without affecting the coherence time of the NV spin state. The results proved that this system can quantitatively detect the light-matter interaction at nanoscale, and it provides an approach to enhance the fluorescence intensity of a quantum emitter.
精确探测表面等离激元对于研究纳米光子学和量子光学至关重要。在本研究中，我们使用金刚石中的单个氮空位中心作为探针，探测由金属膜厚度调制的表面等离激元。通过测量氮空位（NV）中心的荧光强度和寿命，我们获得了局域光物质相互作用的信息。我们观察到表面等离激元的非线性厚度依赖性变化，在大约 30nm 的厚度处达到最大值。通过优化银膜的厚度，单个 NV 中心的荧光强度增强了 2.6 倍，寿命减少了 1/3，同时不影响 NV 自旋态的相干时间。实验结果证明，该系统可以定量探测纳米尺度的光物质相互作用，并为增强量子发射器的荧光强度提供了一种方法。
