提出了一种基于硫化铅(PbS)光纤的折射率/曲率不敏感的光纤温度传感器。该传感器制作简单，只需将一段PbS光纤无错位熔接在两段单模光纤之间即可。由于PbS光纤纤芯特殊的折射率分布，当光线由输入单模光纤进入PbS光纤时，它会在PbS光纤纤芯中激发出不同的模式，不同模式在进入输出单模光纤时将会发生干涉。当外界环境温度变化时，PbS光纤中不同模式间的光程差将会发生变化，从而引起传感器传输光谱的变化，因此可以通过检测传输光谱的变化实现对外界温度的测量。通过实验发现，PbS光纤长度为4 mm时，即可得到完整的周期性干涉谱。对该传感器进行温度、折射率与曲率传感实验，可得温度灵敏度为55.45 pm/℃，折射率灵敏度为2.08 nm/RIU(其中RIU为单位折射率)，曲率灵敏度为-0.29 nm/m-1，说明该传感器对折射率和曲率不敏感，避免了温度测量时，折射率与曲率对其的影响。该传感器具有很小的结构尺寸，能够很好地应用在生物化学、工业生产等的温度测量场合。

A refractive index and curvature insensitive temperature sensor based on PbS fiber is proposed. It is simple in fabrication just by splicing a section of PbS fiber between two single mode fibers without dislocation. Due to the special refractive index distribution of the PbS fiber core, the light can be stimulated to different modes in the core when it couples into the PbS fiber from the input single mode fiber. Different modes interfere when they couple into the output single mode fiber. The optical path differences between different modes of the PbS fiber change when the ambient temperature changes. Finally, the transmission spectrum of the sensor has a variation. Monitoring the variation of the transmission spectrum can measure the ambient temperature. Through the experiments, it is found that a complete periodic interference spectrum can be obtained when the length of PbS fiber is 4 mm. The sensing performances of temperature, refractive index and curvature of the sensor are tested, respectively. The results show that the temperature sensitivity of the sensor is 55.45 pm/℃, the refractive index sensitivity is only 2.08 nm/RIU and the curvature sensitivity is only -0.29 nm/m-1, in which RIU is refractive index unit. It means that the sensor is insensitive to refractive index and curvature. So the temperature sensor can avoid the impact of the refractive index and the curvature. The sensor has a small structure size, and it can be well used in biochemistry, industrial production and other temperature measurement occasions.