论文部分内容阅读
利用时域有限差分法分别模拟计算了X型金纳米结构和L型纳米天线以及由这两种结构所组成的金纳米交叉结构的消光光谱和近场分布,并研究了金纳米交叉结构对周围介质折射率变化的敏感性。研究结果表明,X型金纳米结构在入射光正入射时能激发起偶极共振模式而在斜入射时可以同时激发起偶极和四极共振模式。L型纳米天线的成键和反成键共振模式的产生可以通过改变入射光偏振方向进行控制。此外入射光偏振方向变化时在金纳米交叉结构中都可产生法诺共振效应,由于激发起法诺共振效应,金纳米交叉结构的光谱线型更加精细,传感质量因子可达到12.5,这些结果可指导金纳米交叉结构作为纳米光子器件用于生物传感方面。
The time-domain finite difference method was used to simulate the extinction spectra and the near-field distribution of the X-type gold nanostructures and the L-type nanowires respectively and the gold nanocross structure composed of these two structures. The effects of gold nanocross structure on the surrounding Sensitivity of medium refractive index change. The results show that X-type gold nanostructures can initiate dipole resonance mode when incident light is incident and dipole and quadrupole resonance modes can be excited simultaneously when oblique incident. The formation of L-shaped nanowire bonding and anti-bonding resonance modes can be controlled by changing the polarization direction of incident light. In addition, when the polarization direction of incident light changes, the Farno resonance effect can be produced in the gold nanocross structure. Due to the Farano resonance effect, the spectral line shape of the gold nanocross structure is finer and the sensing quality factor can reach 12.5. These results It can guide the gold nanocross structure as a nano-photonic device for biosensing.