研究了Kretschmann型表面等离子体共振(SPR)结构中电介质折射率、柱面镜折射率以及金属膜厚度对SPR场增强表面增强拉曼散射(SERS)信号的影响。实验结果表明SPR与SERS之间存在着本质上的相关性,电介质折射率、耦合柱面镜折射率以及金属膜厚度均对SPR场增强SERS有较大影响。相同条件下,电介质的折射率越小,SPR场对SERS信号的增强越强,激发的SERS信号的强度越大;柱面镜折射率越大,SPR对SERS的增强越明显;SERS信号强度随着银膜厚度的增加先增大后减小,在银膜厚度为47nm左右时SERS强度有最大值。
The effects of dielectric refractive index, prism refractive index and metal film thickness on the surface plasmon resonance (SPR) field enhanced surface-enhanced Raman scattering (SERS) with Kretschmann SPR configuration are studied. Experimental results show that SPR and SERS are essentially correlative. The dielectric refractive index, prism refractive index and metal film thickness have a large effect on SPR field enhanced SERS. Under the same condition, when the dielectric refractive index is small, the SPR field used for SERS signal enhancement and the SERS are great. When the prism refractive index is great, the SPR field enhanced SERS is great. When the silver film thickness increases, the SERS signal intensity increases at first, and then decreases after the SERS signal reaches the largest value. When the silver film thickness is about 47 nm, the SERS signal is the largest.