Hu W Q, Liang E J, Ding P, Cai G W, Xue Q Z
Department of Applied Physics, Donghua University, Shanghai, China.
Opt Express. 2009 Nov 23;17(24):21843-9. doi: 10.1364/OE.17.021843.
A #-shaped gold wires metamaterial is designed for surface enhanced Raman spectroscopy (SERS) and sensing. The tunability of surface plasmon resonance (SPR) excitations, hotspots distribution, localized field enhancement and sensitivity of the structure are investigated. In contrast to most metamaterial, the #-shaped structure exhibits two pronounced SPRs that are insensitive to the polarization of excitation light. Pure electromagnetic Raman enhancement factors of about 10(6) are achieved on the symmetrically distributed field hotspots. It is possible to break the usable wavelength range of conventional gold SERS substrates via higher order excitations of the #-shaped metamaterial. In addition, the sensitivity and the figure of merits are found to be comparable or even higher than those of conventional SERS substrates. All these factors together with the high reproducibility nature of metamaterial and its simple planer structure suggest that this structure is very promising for surface enhanced spectroscopy and sensing applications.
一种用于表面增强拉曼光谱（SERS）和传感的井字形金线超材料被设计出来。研究了该结构的表面等离子体共振（SPR）激发的可调性、热点分布、局部场增强和灵敏度。与大多数超材料不同，井字形结构展现出两个对激发光偏振不敏感的明显SPR。在对称分布的场热点上实现了约10(6)的纯电磁拉曼增强因子。通过井字形超材料的高阶激发有可能突破传统金SERS基底的可用波长范围。此外，发现该结构的灵敏度和品质因数与传统SERS基底相当甚至更高。所有这些因素，再加上超材料的高再现性及其简单的平面结构，表明这种结构在表面增强光谱和传感应用方面非常有前景。
