提出一种基于表面等离子体共振的双芯光子晶体光纤温度传感器, 其中双芯光子晶体光纤为折射率导光型, 其中心圆孔表面镀氮化钛薄膜, 内部填充具有较大热敏系数的乙醇和氯仿的混合液体, 其纤芯模与表面等离子体激元耦合的共振波长偏移可反映液体混合物的温度或折射率.利用全矢量有限元法分析了不同因素对传输损耗谱及其共振波长的影响.仿真结果表明：外包层空气孔直径增大, 以及最内层包层空气孔直径和空气孔间距减小可以提高耦合效率, 从而增强共振峰.对比分析发现在－20℃~ 120℃温度范围内, 氮化钛薄膜比传统金膜表现出更好的等离子传感特性, 随着膜厚增加, 其共振波长偏移量增加, 温度灵敏度提高, 灵敏度最高可以达到6.22 nm/K.

A dual-core photonic crystal fiber temperature sensor based on the surface-plasmon-resonance was proposed. The holey analyte channel in the center of the index-guiding dual-core photonic crystal fiber is coated with a titanium nitride layer and filled with a liquid mixture of ethanol and chloroform exhibiting a large thermo-optic coefficient. The shift of the resonance wavelength for the coupling between the guided-core mode and surface-plasmon-polariton reflects the variation of temperature or refractive index of the infiltrated liquid mixture. With the full-vector finite element method, the impacts of various factors on the transmission loss spectrum and its resonance wavelength were analyzed. The numerical calculation indicates that by any of the means of increasing the outer-cladding-hole diameter and decreasing the innermost-cladding-hole diameter or the hole pitch, the coupling efficiency, namely the resonance amplitude, can be increased. It is found that titanium nitride film shows superior surface-plasmon-resonance sensing characteristics over conventional gold film in the temperature range of －20℃~ 120℃, featuring an increase of both resonance wavelength shift and temperature sensitivity with an increase of film thickness and attaining the maximum temperature sensitivity of 6.22 nm/K.