King Abdullah University of Science and Technology, PSE and BESE Divisions, Thuwal, 23955-6900, Saudi Arabia.
Sci Rep. 2017 Sep 5;7(1):10524. doi: 10.1038/s41598-017-11140-0.
We present a theoretical approach to narrow the plasmon linewidth and enhance the near-field intensity at a plasmonic dimer gap (hot spot) through coupling the electric localized surface plasmon (LSP) resonance of a silver hemispherical dimer with the resonant modes of a Fabry-Perot (FP) cavity. The strong coupling is demonstrated by the large anticrossing in the reflection spectra and a Rabi splitting of 76 meV. Up to 2-fold enhancement increase can be achieved compared to that without using the cavity. Such high field enhancement has potential applications in optics, including sensors and high resolution imaging devices. In addition, the resonance splitting allows for greater flexibility in using the same array at different wavelengths. We then further propose a practical design to realize such a device and include dimers of different shapes and materials.
我们提出了一种理论方法，通过将银半球二聚体的局域表面等离激元（LSP）共振与法布里-珀罗（FP）腔的共振模式耦合，来缩小等离子体二聚体间隙（热点）处的等离子体线宽并增强近场强度。强耦合由反射光谱中的大反交叉和 76 meV 的拉比分裂证明。与不使用腔的情况相比，可实现高达 2 倍的增强增加。这种高场增强在光学领域具有潜在的应用，包括传感器和高分辨率成像设备。此外，共振分裂允许在不同波长下使用相同的阵列具有更大的灵活性。然后，我们进一步提出了一种实际的设计来实现这种器件，并包括不同形状和材料的二聚体。
