Zhu Wanlai, Xu Feng, Yi Zao, Cheng Shubo, Yang Hua, Wu Xianwen, Li Gongfa, Zeng Liangcai, Yu Zhenfang, Li Hailiang
Joint Laboratory for Extreme Conditions Matter Properties, Key Laboratory of Manufacturing Process TestingTechnology of Ministry of Education, State Key Laboratory of Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China.
College of Chemical Engineering and Materials Science, Quanzhou Normal University, Quanzhou 362000, China.
Phys Chem Chem Phys. 2023 Jul 26;25(29):19596-19605. doi: 10.1039/d3cp01615c.
To further reduce the fabrication difficulty of optical fiber sensors and improve the sensing performance, this study introduced the surface plasmon resonance (SPR) effect into optical fiber sensing technology and designed an eccentric-core photonic crystal fiber (EC-PCF). We investigated the characteristics of the two fundamental modes in the fiber core and the surface plasmon polariton (SPP) modes on the surface of the gold film. We also investigated the influence of the structural parameters, such as gold film coating area and thickness, air hole diameter, and eccentricity, on the confinement loss and achieved a refractive index (RI) sensitivity of 31.25 μm RIU in the RI range of 1.29-1.43, corresponding to a figure of merit (FOM) of 521.6 per RIU. When the resolution of the optical spectrum analyzer was 0.1 nm, the EC-PCF could achieve a refractive index resolution of 3.2 × 10 RIU. Moreover, we performed tests with two typical sensing types, one in which the sensor was directly in contact with adulterated gasoline to achieve kerosene-concentration detection, and another in which the sensor was coated with a layer of polydimethylsiloxane (PDMS), whose RI is sensitive to the temperature field, to achieve temperature sensing. The EC-PCF demonstrated excellent sensing performance and offers obvious manufacturing advantages, providing a new and easily fabricated structural design idea for optical fiber sensing.
为进一步降低光纤传感器的制造难度并提高传感性能，本研究将表面等离子体共振（SPR）效应引入光纤传感技术，并设计了一种偏心芯光子晶体光纤（EC-PCF）。我们研究了纤芯中的两种基模以及金膜表面的表面等离子体激元（SPP）模的特性。我们还研究了诸如金膜涂层面积和厚度、气孔直径和偏心度等结构参数对限制损耗的影响，并在1.29 - 1.43的折射率范围内实现了31.25μm/RIU的折射率（RI）灵敏度，对应每RIU 521.6的品质因数（FOM）。当光谱分析仪的分辨率为0.1nm时，EC-PCF可实现3.2×10⁻⁵RIU的折射率分辨率。此外，我们进行了两种典型传感类型的测试，一种是传感器直接与掺假汽油接触以实现煤油浓度检测，另一种是传感器涂覆一层折射率对温度场敏感的聚二甲基硅氧烷（PDMS）以实现温度传感。EC-PCF展示了优异的传感性能并具有明显的制造优势，为光纤传感提供了一种新的且易于制造的结构设计思路。
