Strong Near-Field Coupling of Plasmonic Resonators Embedded in Si Nanowires
详细信息 查看全文
- 作者：Dmitriy S. Boyuk ; Li-Wei Chou ; Michael A. Filler
- 刊名：ACS Photonics
- 出版年：2016
- 出版时间：February 17, 2016
- 年：2016
- 卷：3
- 期：2
- 页码：184-189
- 全文大小：488K
- ISSN：2330-4022
文摘
The strength of localized surface plasmon resonance (LSPR) near-field interactions scales in a well-known, nearly universal manner. Here, we show that embedding resonators in an anisotropic dielectric with a large permittivity can substantially increase coupling strength. We experimentally demonstrate this effect with Si nanowires containing two phosphorus-doped segments. The near-field decay length scaling factor is extracted from in situ infrared spectral response measurements using the “plasmon ruler” equation and found to be ca. 4−5 times larger than for the same resonators in isotropic vacuum or Si. Discrete dipole approximation calculations support the observed coupling behavior for nanowires and show how it is affected by the resonator geometry, carrier density, and embedding material (Si, Ge, GaAs, etc.). Our findings demonstrate that equivalent near-field interactions are achievable with a smaller total volume and/or at increased resonator spacing, offering new opportunities to engineer plasmon-based chemical sensors, catalysts, and waveguides.