三角形硅二聚体纳米天线及其荧光增强效应研究

Research on Triangular Silicon Dimer Nano-antenna and Its Fluorescence Enhancement Effect

摘要:

提出了一种三角形硅二聚体纳米天线结构,该结构可以从激发和发射过程同时提高荧光物质的荧光发光效率,并且实现荧光的远场定向发射增强。利用时域有限差分法详细研究了不同组合方式的三角形二聚体、不同三角形直角边长以及不同二聚体底角间距对荧光发射增强效果的影响,并进行了结构参数的优化,研究了该结构对荧光激发过程的影响。结果表明,三角形硅二聚体纳米天线结构的直角边长为300nm,二聚体底角间距为0nm是纳米天线的最优参数。相对于裸光源,硅二聚体纳米天线使点光源的荧光发射增强了7倍,实现了远场定向发射。而且,在405nm波长光的激发下,荧光激发过程也得到了增强。

Abstract:

In this work, a triangular silicon dimer nano-antenna structure was proposed, which can improve the fluorescence emission efficiency of the dipole source in the excitation and emission process at the same time, and realize the enhancement of far-field directional emission. The effects of the combination of the dimer, the size of the triangle's right-angle side, and the spacing of the dimer on the enhancement effect of fluorescence emission were studied by using the finite difference time domain method, and the structural parameters were optimized. Finally the effect of the structure on the fluorescence excitation process was studied. The results show that the triangular silicon dimer nano-antenna structure with the right-angle side length of 300nm and the dimer spacing of 0nm are the optimal parameters of the nano-antenna. Compared with the bare light source, the fluorescence emission intensity of silicon dimer nano-antenna is increased by 7 times, and the far-field directional emission is realized. Moreover, under the excitation of 405nm wavelength light, fluorescence excitation enhancement can be achieved.