基于表面等离子体共振的4杆悬浮芯光纤折射率传感仿真分析

Refractive Index Sensing Simulation Analysis of Four-Pole Suspended Core Fiber Based on Surface Plasmon Resonance

设计了一种小芯径的4杆悬浮芯光纤折射率检测传感器,并针对这种光纤模拟了三种不同的抛磨结构。通过在开放式的气孔中涂覆金膜来激发表面等离子体共振效应。采用有限元方法(FEM)分析了开放式悬浮芯光纤的表面等离子体传感特性,并研究了传感金属层和悬浮杆厚度对传感效果的影响。单孔抛磨结构和相对两孔抛磨结构的折射率检测范围为1.31~1.42,最大灵敏度分别为15000 nm/RIU(refractive index unit)和16000 nm/RIU,分辨率分别为6.7×10^(-6) RIU和6.25×10^(-6) RIU。相邻两孔抛磨结构的折射率检测范围为1.31~1.40,最大灵敏度可达20000 nm/RIU,分辨率可达5.0×10^(-6) RIU。此传感器在测量高折射率物质方面具有很好的性能,便于制备,将来有广阔的市场应用前景。

A refractive index detection sensor for four-pole suspended core fibers with a small core diameter is designed,and three different polishing structures are simulated for this fiber.The open air holes are coated with gold film to stimulate the surface plasmon resonance effect.The finite element method(FEM)is used to analyze the surface plasmon sensing characteristics of the open suspended core fiber,and the influences of the geometric parameters of the sensing metal layer and the thickness of the suspended poles on the sensing effect are studied.The single-hole polishing structure and the opposite two-hole polishing structure have a refractive index detection range of 1.31—1.42,the maximum sensitivities are 15000 nm/RIU(refractive index unit)and 16000 nm/RIU,and the resolutions are 6.7×10^(-6) RIU and 6.25×10^(-6) RIU,respectively.The refractive index detection range of the adjacent two-hole polishing structure is 1.31—1.40,the maximum sensitivity can reach 20000 nm/RIU,and the resolution can reach 5.0×10^(-6) RIU.This sensor has good performance in measuring high refractive index substances,is easy to prepare,and has broad market application prospects in the future.