A vibration sensor based on Sagnac interferometer and fiber ring laser (FRL) is proposed for fault diagnosis of bearing, and a sensing system of vibration is demonstrated experimentally. In the sensing system, the Sagnac interferometer based on single mode fiber- polarization maintaining fiber-single mode fiber (SPS) as a sensor is connected to FRL which performs as a filter. Because the transmission characteristics of the SPS is modulated by strain, intensity-modulated sensing is induced for output power of the FRL. Experimental result shows that the accurate frequency of the vibration signal within relative error of 1.0% can be obtained by the sensor. The proposed sensor has the advantages of low-cost, compact size, easy to be fabricated and excellent anti-interference ability, which has potential applications on the bearing fault diagnosis of rotating machinery.

提出了一种基于萨格纳克干涉仪和光纤环形激光器（FRL）的振动传感器，用于轴承的故障诊断，并通过实验对振动传感系统进行了演示。在传感系统中，基于单模光纤偏振保持光纤单模光纤（SPS）作为传感器的Sagnac干涉仪连接到充当滤波器的FRL。由于SPS的传输特性是通过应变进行调制的，因此会为FRL的输出功率引入强度调制传感。实验结果表明，该传感器能够获得相对误差在1.0％以内的准确的振动信号频率。所提出的传感器具有成本低，尺寸紧凑，易于制造，抗干扰能力强的优点，