Design and Performance of Fiber Vibration Sensor Based on Fabry–Perot Structures With Microbubble

Microbubble Fabry–Perot optical fiber vibration sensor has been proposed and used for monitoring the external vibration through its unique ultrathin silicon film. The vibration signal deforms the silicon film and changes the intensity of reflected light, so as to establish their depending relationship. In this article, the fabrication method of microbubble Fabry–Perot optical fiber vibration sensing probe as well as the flexible adjustment method of Fabry–Perot cavity length are analyzed and discussed. By comparing the frequency response of microbubble cavity structures with different parameters, the influence law of the cavity morphology on the vibration sensing performance has been studied. The designed vibration sensor based on the microbubble Fabry–Perot interference cavity has a small size, compact structure, and high sensitivity, which is suitable for real-time monitoring of static pressure and dynamic vibration in complex environment, such as narrow space. This work can provide some theoretical and technical reference for developing the miniature vibration sensor devices with high performance.