Fano共振效应拥有独特的局域场增强效果, 在表面增强相干反斯托克斯拉曼散射中, 不同波长局域场增强空间位置相同的结构结合Fano共振效应, 可以实现“混合频率共振模式”, 使得表面增强相干反斯托克斯拉曼散射总的增强因子得到大幅度提高。采用FDTD软件系统研究了对称的交叉蝴蝶结Au纳米结构的Fano共振效应, 该效应使得交叉蝴蝶结结构中心位置附近的电场强度得到大幅度的增强, 把该结构应用到表面增强相干反斯托克斯拉曼散射中, 可以使表面增强相干反斯托克斯拉曼散射信号的增强因子高达1013, 达到单分子检测的水平。

Fano resonance is a special effect which can greatly enhance the intensity of the local electric field. For a nanostructure, if the hot spots of different wavelengths are in the same spatial position and the scattering spectrum has a Fano lineshape, the enhancement factor of surface enhanced coherent anti-Stokes Raman scattering can be hugely increased. The Fano resonance effect of a symmetric cross bowtie Au nanostructure was studied by FDTD software, the electric field of the "hot spots" near the middle of the structure was greatly enhanced. In surface enhanced coherent anti-Stokes Raman scattering, this structure can make the enhancement factor to be as high as 1013, enabling the detection of single molecules.