基于双D型光纤表面等离子共振折射率传感研究

Study on Refractive Index Sensing Based on Double DType Surface Plasmon Resonance

摘要:

以双D型光纤作为传输载体,研究了一种基于表面等离子共振技术的双D型光纤折射率传感器。利用时域有限差分法,分析了双D型光纤剩余包层厚度、金膜厚度、金膜表面粗糙度以及双通道传输对光纤SPR传感器性能的影响。仿真结果表明,当剩余包层厚度为300~500nm、覆盖的金膜厚度为50nm时,双D型光纤SPR传感器的性能得到优化;金膜表面粗糙度也是影响传感器性能的重要因素,当金膜表面粗糙度的均方根值低于2nm或其相关长度大于160nm时,金膜表面粗糙度对传感器性能的影响显著减小,且在折射率为1.33~1.36的传感环境下具有较好的线性度;在双D型光纤两侧覆不同的金属膜,可以实现信号的双通道测量。

Abstract:

Taking double Dtype fiber as the transmission carrier, a double Dtype fiber sensor based on surface plasmon resonance (SPR) sensing technology was studied. Using finitedifference timedomain method, the effects of residual cladding thickness, gold film thickness, gold film surface roughness, and dualchannel transmission on the performance of optical fiber SPR sensor were analyzed. Simulation results show that its performance is optimized when the thickness of the remaining cladding is 300~500nm and the thickness of the covered gold film is 50nm. The roughness of the gold film is also an important factor affecting the performance of the sensor, when its RMS value is less than 2nm or its correlation length is greater than 160nm, the influence of the roughness of gold film surface on the sensor performance can be significantly reduced and the sensor has a good linearity in the sensing environment with the refractive index of 1.33~1.36. When two different types of metal films are coated on both sides of a double Dtype fiber, dualchannel measurements of the signal can be achieved.