Department of Physics, Korea University, Seoul 136-701, South Korea.
Opt Lett. 2011 Jun 1;36(11):2011-3. doi: 10.1364/OL.36.002011.
We propose an ultrasmall plasmonic cavity consisting of a high-index/low-index dielectric nanorod covered with silver. Full three-dimensional subwavelength confinement of the surface-plasmon polaritons was achieved at the high-index dielectric-silver interface without propagating to the low-index dielectric-silver interface. The numerical simulations showed that the plasmonic mode excited in this cavity has a deep subwavelength mode volume of 0.0038(λ/2n)(3) and a quality factor of 1500 at 40 K, and consequently a large Purcell factor of ∼2×10(5). Therefore, this plasmonic cavity is expected to be useful for the demonstration of high-efficiency single photon sources or low-threshold lasers in an ultracompact nanophotonic circuit.
我们提出了一种由高折射率/低折射率介质纳米棒覆盖银组成的超小等离子体腔。在没有传播到低折射率介质-银界面的情况下，表面等离激元在高折射率介质-银界面处实现了完全的三维亚波长限制。数值模拟表明，该腔中激发的等离子体模式具有 0.0038(λ/2n)(3)的深亚波长模式体积和在 40 K 时的 1500 的品质因数，因此具有约 2×10(5)的大 Purcell 因子。因此，这种等离子体腔有望用于在超紧凑的纳米光子电路中演示高效率的单光子源或低阈值激光器。
