石墨烯-金属纳米线阵列增敏等离子体光纤传感器

Sensitivity Improvement of Plasmonic Optical Fiber Sensors with Graphene-Metal Nanowire Array

设计了一种新颖的石墨烯-金属纳米线阵列结构等离子体D型光纤传感器。在纤芯上利用石墨烯与金属纳米线产生的局域表面等离子体共振(LSPR)特性,达到提高折射率灵敏度的效果。采用全矢量有限元法对该结构等离子体模和纤芯模的色散关系进行分析,同时研究金属传感层厚度和金纳米线直径对传感器性能的影响,最后对三种不同结构(金膜结构、石墨烯-金膜-石墨烯结构、石墨烯-金属纳米线阵列结构)传感器的灵敏度进行比较。结果表明,采用优化后的结构参数,可使所设计的基于石墨烯-金属纳米线阵列结构的传感器灵敏度得到极大的提升。折射率为1.33~1.40时,所设计结构的最高灵敏度为7383.79 nm/RIU,平均灵敏度为4136.00 nm/RIU。该研究结果为下一代等离子体光纤传感器设计提供了理论依据。

A novel plasmonic D-shaped optical fiber sensor with a graphene-metal nanowire array structure was designed.The refractive index sensitivity was improved on the core by using the localized surface plasmon resonance(LSPR)produced by graphene and metal nanowires. The full-vector finite-element method was utilized to investigate the dispersion relationship between the plasmonic mode and the core mode of the structure. The effects of the thickness of the metal sensing layer and the diameter of the metal nanowires on the sensor’s performance were also examined. Finally, the sensitivity of three types of sensors with different structures(gold film structure, graphene-gold film-graphene structure,and graphene-metal nanowire array structure) was compared. The results reveal that adopting the optimized structural parameters considerably improves the sensitivity of the developed sensor based on the graphene-metal nanowire array structure. Specifically, when the refractive index is between 1. 33 and 1. 40, the design structure obtains a maximum sensitivity of 7383. 79 nm/RIU and an average sensitivity of 4136. 00 nm/RIU. The findings of this study serve as a theoretical foundation for the development of next-generation plasmonic optical fiber sensors.