A novel half-side PDMS-coated photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR) is proposed for simultaneous detection of seawater salinity and temperature. The plasmonic material gold is coated on the outer surface of the PCF to measure the seawater salinity by exciting SPR effect. Moreover, the polydimethylsiloxane (PDMS) layer is coated on the upper half-side of the surface of the sensor as an independent temperature sensing channel. The properties of modes coupling between surface plasmon polaritons (SPPs) mode and four different core modes are investigated. Meanwhile, the influence of various geometrical parameters on the sensing characteristics are theoretically simulated by using finite element method (FEM). The numerical results show that the salinity sensitivity of the designed sensor can reach 0.307 nm/‰ with a resolution of 0.3257‰. Additionally, the temperature sensitivity of −4.937 nm/°C with the resolution of 0.0203 °C in the sensing range from 25 °C to 50 °C has been obtained. The proposed sensor, possessing advantages such as ease of fabrication, excellent sensing performance and low cost, not only realizes the simultaneous measurement of two parameters, but also has potential in the field of seawater monitoring.

提出了一种基于表面等离子体共振 (SPR) 的新型半边 PDMS 涂层光子晶体光纤 (PCF) 传感器，用于同时检测海水盐度和温度。等离子体材料金涂覆在PCF的外表面，通过激发SPR效应测量海水盐度。此外，聚二甲基硅氧烷（PDMS）层涂覆在传感器表面的上半侧，作为独立的温度传感通道。研究了表面等离子体激元 (SPP) 模式和四种不同核心模式之间的模式耦合特性。同时，利用有限元法（FEM）从理论上模拟了各种几何参数对传感特性的影响。数值结果表明，所设计传感器的盐度灵敏度可达0。307 nm/‰，分辨率为0.3257‰。此外，在 25°C 至 50°C 的传感范围内获得了 -4.937 nm/°C 的温度灵敏度和 0.0203°C 的分辨率。所提出的传感器具有易于制造、传感性能优良、成本低等优点，不仅实现了两个参数的同时测量，而且在海水监测领域具有潜力。