基于等离子波导的表面增强拉曼芯片仿真分析

Simulation Analysis of Surface-enhanced Raman Scattering Chip Based on the Plasma Waveguide

本文设计了一种基于长程等离子波导的表面增强拉曼光流体芯片,利用介质波导激发等离子波导的耦合结构减小传输损耗,增加传输距离,以实现拉曼信号的长程探测。在632.8 nm的激发光入射下,以金(Au)作为等离子波导芯层材料,PTFE做为介质光波导芯层材料,经仿真分析发现:介质光波导宽度为4 m、厚度为0.2 m,等离子体波导宽度为4.5 m、厚度为13 nm,两波导间距D为3.1 m时,耦合效果最好,场强大小约1.8024×10^8,传输距离约0.3 mm,是单独使用等离子波导传输距离的两倍。该研究为实现表面增强拉曼微流体芯片长程探测提供了理论依据。

In this paper,a surface-enhanced Raman scattering optical fluid chip based on long-range plasma waveguide is designed.The dielectric waveguide is used to excite plasma waveguide.The coupling signal transmit through the plasma waveguide and dielectric waveguide.It may reduce the transmission loss and increase transmission distance.The excitation light of 632.8 nm is used.The gold(Au)is as a plasma waveguide core layer and PTFE is as dielectric optical waveguide core layer.The simulation results show that the dielectric optical waveguide width of 4 m,thickness of 0.2 m,plasma waveguide width of 4.5 m,thickness of 13 nm,the spacing D between two waveguide of 3.1 m,coupling effect is best.The field intensity is about 1.8024×108 and the transmission distance is about 0.3 mm which is twice of used alone the plasma waveguide transmission distance.This study provides a theoretical basis for long-range detection of surface-enhanced Raman microfluidic chip.