提出一种基于锥形光纤和光纤F-P腔组合结构的光纤应变传感器。该传感器包含单模光纤拉锥形成的锥区和石英毛细管构建的F-P腔2个应变敏感区域。理论分析了光波在该传感器中的传播过程，获得了该传感器的光强传输函数。由于锥形光纤中激发出的包层高阶模参与干涉，导致传感器干涉光谱具有调制特性。实验获得了该传感器的干涉光谱，通过分析谐振波长偏移或消光比变化对应变实现独立测量，在0～500 με的测量范围内，该传感器的应变灵敏度为14.6 pm/με。利用锥形光纤引发的模式干涉和F-P腔的双光束干涉效应共同作用形成受调制的干涉谱型进行应变传感，应变灵敏度高，同时具备2种独立的应变检测手段(谐振波长和消光比检测)。

A fiber-optics strain sensor based on the composite structure of tapered fiber and fiber Fabry-Pérot(F-P) interferometer was proposed and experimentally demonstrated, which comprised 2 strain sensitive regions,the tapered region formed by single mode fiber taper and the F-P cavity based on the quarts capillary tube. The propagation process of light waves in the sensor was analyzed theoretically,and the light intensity transfer function was obtained . As the cladding high-order mode excited by tapered fiber participated in interference, the interference spectrum of sensor had modulation characteristics.The interference spectrum of sensor was obtained by experiment and the independent measurement was realized by analyzing the resonant wavelength shift or extinction ratio change. Experimental results indicate that the proposed sensor presents a sensitivity of 14.6 pm/με in the measurement range from 0 to 500 με Using the modulated interference spectrum formed by the tapered fiber induced mode interference and the double-beam interference of the F-P cavity to conduct strain sensing , the strain sensitivity is high, and 2 kinds of independent strain detection methods (resonant wavelength and extinction ratio detection ) can be provided.