The local density of optical states governs an emitters’ lifetime and quantum yield through the Purcell effect. It can be modified by a surface plasmon electromagnetic field, but such a field has a spatial extension limited to a few hundreds of nanometers, complicating the use of optical methods to spatially probe emitter–plasmon coupling. Here we show that a combination of electron-based imaging, spectroscopies, and photon-based correlation spectroscopy enables measurement of the Purcell effect with nanometer and nanosecond spatiotemporal resolutions. Due to the large variability of radiative lifetimes of emitters in nanoparticles we relied on a statistical approach to probe the coupling between nitrogen-vacancy centers in nanodiamonds and surface plasmons in silver nanocubes. We quantified the Purcell effect by measuring the nitrogen-vacancy excited state lifetimes in a large number of either isolated nanodiamonds or nanodiamond-nanocube dimers and demonstrated a significant lifetime reduction for dimers.

中文翻译：

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用光子和快速电子探测纳米级的Plasmon-NV ⁰耦合

光学状态的局部密度通过珀塞尔效应控制着发射器的寿命和量子产率。可以通过表面等离激元电磁场对其进行修改，但是这种场的空间扩展仅限于几百纳米，这使得使用光学方法在空间上探测发射极-等离激元耦合变得复杂。在这里，我们展示了基于电子的成像，光谱学和基于光子的相关光谱学的组合，可以测量具有纳米和纳秒时空分辨率的赛尔效应。由于纳米粒子中发射体的辐射寿命差异很大，我们依靠统计方法来探测纳米金刚石中的氮空位中心与银纳米立方体中的表面等离子体激元之间的耦合。