中文摘要：

根据马赫-曾德尔干涉（MZI）原理,在两段标准单模光纤（SMF）中间腰椎放大熔接长为2cm的细芯SMF（TCSMF）,构成光纤传感器。利用TCSMF的包层模、纤芯模对折射率和温度的灵敏度差异,通过检测透射光谱中不同级次的干涉谷的特征波长变化,结合敏感矩阵实现对折射率/温度的双参数同时测量。实验选取在1 502.54nm波长处干涉谷的折射率和温度的灵敏度分别为270.517 1nm/RIU（其中RIU为折射率单位）和19.3pm/℃;在1 521.64nm波长处干涉谷的折射率灵敏度为239.510 3nm/RIU,对温度不敏感。根据0.01nm波长分辨率的光谱仪（OSA）,本文光纤传感器对折射率和温度的分辨率分别为3.6966×10-5 RIU和0.5181℃,也可以应用于其他参数的测量,具有良好的应用和发展前景。

英文摘要：

A fiber sensor based on Mach-Zehnder interference（MZI）for simultaneously measuring refractive index and temperature is proposed in this paper.The fiber sensor is constructed by waist-enlarging a 2cm thin-core single-mode fiber between two conventional single-mode fibers.By observing the wavelength shifts of different interference dips and using the sensitivity matrix,refractive index and temperature can be measured simultaneously,since the core modes and the cladding modes have different sensitivities to these two external parameters.Experimental results indicate that refractive index and temperature sensitivities of the wavelength dips at 1502.54 nm are 270.5171nm/RIU and 19.3pm/℃,the refractive index sensitivity of the wavelength dip at 1521.64 nm is 239.5103nm/RIU and whereas the temperature is insensitive.The proposed fiber sensor can reach a resolution of 3.696 6×10-5 RIU for refractive index and 0.518 1℃for temperature.