Fedotova Yana V, Kukushkin Vladimir I, Solovyev Victor V, Kukushkin Igor V
Opt Express. 2019 Oct 28;27(22):32578-32586. doi: 10.1364/OE.27.032578.
Exceptionally strong enhancement of the Raman signal exceeding eight orders of magnitude for near-infrared (1064 nm) excitation is demonstrated for an array of dielectric submicron pillars covered by a relatively thick metal layer. The microstructure is designed to support 'spoof' plasmon-polariton excitations with resonant frequencies significantly below the fundamental surface plasmon resonance. Experiments reveal a relatively narrow range of spatial parameters for the optimal resonant scattering enhancement. They include a period close to the excitation wavelength, a specific ratio of the pillar planar size to the period, and optimal heights of both the pillars and the covering silver metal layer. The realized microstructures can be produced by fab-compatible photolithography techniques, and their outstanding sensing possibilities open the venue for the biomedical applications.
对于覆盖有相对较厚金属层的介电亚微米柱阵列，在近红外（1064nm）激发下，拉曼信号实现了超过八个数量级的超强增强。该微观结构被设计用于支持“类”表面等离激元 - 极化激元激发，其共振频率显著低于基本表面等离激元共振频率。实验揭示了实现最佳共振散射增强的空间参数范围相对较窄。这些参数包括接近激发波长的周期、柱平面尺寸与周期的特定比率，以及柱和覆盖银金属层的最佳高度。所实现的微观结构可通过与制造工艺兼容的光刻技术制备，其出色的传感可能性为生物医学应用开辟了道路。
