在单模光纤(SMF)中接入一段硬塑料包层光纤(HPCF)，构成一个全光纤Mach-Zehnder干涉仪，利用该干涉仪制备出一种可同时测量温度和折射率的光纤传感器。由于SMF纤芯和HPCF纤芯直径不匹配，通过HPCF的透射光会产生干涉谱，干涉谱随外界环境温度与折射率的变化而变化，从而可实现温度与折射率的测量。实验结果表明：利用该传感器测量温度与折射率的灵敏度分别达到了13.3 pm·℃-1和52.56 nm·(RIU)-1。该传感器具有体积小、结构简单、制作容易和灵敏度较高等特点，特别适合在电噪声环境中工作。

A fiber sensor which can measure the temperature and refractive index simultaneously is fabricated based on an all-fiber Mach-Zehnder interferometer (MZI). This MZI is formed when a section of a hard plastic cladding fiber (HPCF) is spliced between two sections of single-mode fiber (SMF). Because of mismatching of the core diameters of SMF and HPCF, interference spectrum is generated by the transmission light from the HPCF. As the interference spectrum varies with the change of ambient temperature and refractive index, the simultaneous measurement of temperature and refractive index is realized. Experimental results show that the sensitivity of temperature and refractive index can achieve to 13.3 pm·℃-1 and 52.56 nm·(RIU)-1, respectively. This optical fiber sensor has the characteristics of small volume, simple structure, easy to fabrication and high sensitivity, which is suitable to operate in electrical noisy surroundings.