本文对基于马赫-曾德尔干涉技术的光纤水听器系统进行了实验研究.根据光外差检测原理，利用自制的全光纤马赫-曾德尔干涉仪系统，对鱼群活动引起的扰动信号进行了测量和分析.得到在一定条件下，随着鱼群活动区域面积的增加或温度的降低，探测灵敏度呈线性减小，最小分辨能力下降的结论.实验结果表明：随着活动区域直径的降低，系统灵敏度分别为1.606 6、2.349 9和2.412 5 μW/条，最小分辨力分别为14、10和8条；随着活动区域温度的降低，系统灵敏度分别为1.339 1、1.022 7和0.432 1 μW/条，最小分辨力分别为4、6和18条，测量结果与分析得到的结论一致.

The characteristics of the fiber-optical hydrophone systems based on the all optical fiber Mach-Zehnder′s interferometer were tested and analyzed,according to optical fiber hydrophone working principle.The experimental system was built and the performances of fiber-optic hydrophone were tested in different conditions.The result shows that with the increasing of sphere of fish activities and the decreasing of surrounding temperature,the detection sensitivity is linear decline and the least resolution is decreased,which are corresponded with the calculated ones.