提出并制作了一种马赫增德干涉仪级联光纤布喇格光栅的全光纤传感器,其中马赫增德干涉仪由两个球形结构组成,起分光器和耦合器的作用.分析了各项结构参量对灵敏度的影响,结果表明马赫增德干涉峰和光纤布喇格光栅的透射峰对不同参量的灵敏度不同.实验测得马赫增德干涉峰对温度、折射率和液位的灵敏度分别为0.072 45 nm/℃、87.65 nm/RIU和 0.029 714 nm/mm;光纤布喇格光栅透射峰对温度的灵敏度为0.009 89 nm/℃,但对折射率、液位不灵敏,因此可利用敏感矩阵实现双参量同时测量.该传感器可广泛应用于化学、生物和制药等领域.

A compact optical fiber sensor based on a Mach-Zehnder interferometer embedded in fiber Bragg grating was proposed and experimentally demonstrated. The Mach-Zehnder interferometer is realized by concatenating two spherical-shape structures separated by a middle section. The spherical-shape structures act as a mode splitter and a mode collector,respectively. The effects of different structure parameters of Mach-Zehnder interferometer were discussed. As a result,the resonant wavelength of the fiber Bragg grating and the interference dip of the Mach-Zehnder interferometer have the different sensitivities of temperature,refractive index and liquid level. Experiment results show that the sensitivities of interference dip of Mach-Zehnder interferometer to temperature,refractive and liquid level are 0.072 4 nm/℃,87.65 nm/RIU and －0.029 714 nm/mm,respectively,the resonant wavelength of the fiber Bragg grating has sensitivity of 0.009 89 nm/℃ to temperature,while is insensitive to refractive index and liquid level. The simultaneous measurement of dual parameters can be realized by sensitive matrix. This kind of sensor will have wild applications in chemistry,biology and pharmacy.