Achieving a large enhancement of local electromagnetic fields in the ultraviolet waveband is desirable for some applications such as surface-enhanced Raman scattering and surface-enhanced fluorescence. In addition, it is more significant for some applications such as plasmon-enhanced harmonic generation to enhance the intensity of local electromagnetic fields and increase their decay time at the same time. In this paper, using the finite-difference time-domain method, we numerically demonstrate that using the linearly polarized light with a wavelength of 325 nm as the illumination light, an isolated triangular Al–SiO₂–Al hybrid nanoplate with optimized geometric parameters can produce a local electric field enhanced by a factor of about 108 at one of its top apexes, and produce two local electric fields enhanced by a factor of about 150 at two transverse dielectric/metal interfaces of one of its longitudinal side edges. Moreover, we also numerically demonstrate that the decay time of enhanced local electric fields produced by the isolated triangular Al–SiO₂–Al hybrid nanoplate is about 1.6 times as large as that of enhanced local electric fields produced by an isolated triangular Al nanoplate. These unique properties of the isolated triangular Al–SiO₂–Al hybrid nanoplate arise because of both the transverse coupling and the longitudinal coupling of localized surface plasmon polaritons in this structure. Our findings make triangular Al–SiO₂–Al hybrid nanoplates very promising for application in many fields such as surface-enhanced Raman scattering and plasmon-enhanced harmonic generation.

对于某些应用，例如表面增强拉曼散射和表面增强荧光，需要在紫外波段实现局部电磁场的大幅增强。此外，对于等离子体增强谐波产生等一些应用，增强局部电磁场强度并同时增加其衰减时间更为重要。在本文中，我们使用有限差分时域方法，数值证明了使用波长为 325 nm 的线偏振光作为照明光，一个孤立的三角形 Al-SiO ₂–具有优化几何参数的铝杂化纳米板可以在其顶部之一产生一个增强约 108 倍的局部电场，并在两个横向介电/金属界面处产生两个增强约 150 倍的局部电场。其纵向侧边。此外，我们还通过数值证明了由孤立的三角形 Al-SiO ₂ -Al 混合纳米片产生的增强局部电场的衰减时间大约是由孤立的三角形 Al 纳米片产生的增强局部电场的衰减时间的1.6 倍。孤立的三角形 Al-SiO _{2 的}这些独特性质-Al 混合纳米板的出现是由于该结构中局部表面等离子体激元的横向耦合和纵向耦合。我们的研究结果使三角形 Al-SiO ₂ -Al 混合纳米片在许多领域中的应用非常有前景，例如表面增强拉曼散射和等离子体增强谐波产生。