Signal-to-background ratio of surface-enhanced Raman scattering (SERS) plays an important role in the analytic applications of SERS. Its dependences on excitation wavelength and gap between metal particles were studied theoretically and experimentally. We show that this ratio is higher at smaller gaps for the same excitation wavelength and is higher for the wavelengths having higher values of the absolute values of the dielectric function of the metal. This study thus results in design guidelines in the fabrication of SERS-active substrates with high signal-to-background ratio.

中文翻译：

---

表面增强拉曼散射的信噪比研究：取决于激发波长和热点间隙

表面增强拉曼散射（SERS）的信噪比在SERS的分析应用中起着重要作用。从理论上和实验上研究了其对激发波长和金属颗粒间间隙的依赖性。我们表明，对于相同的激发波长，该比率在较小的间隙处较高，而对于具有较高介电常数的金属绝对值的波长，该比率较高。因此，这项研究为制造具有高信噪比的SERS活性基板提供了设计指南。