A Novel Miniaturized Fiber Bragg Grating Vibration Sensor

Abstract

In order to meet the needs of small space vibration detection, a novel miniaturized fiber Bragg grating (FBG) vibration sensor is proposed. With adopting the hinges and elastic plate as the elastic body, the miniaturization of sensor and suppression of transverse interference are achieved. The suspended FBG can avoid chirp phenomenon and realize distributed measurement. The structure model and principle of the sensor are introduced, the sensing characteristics of the sensor are analyzed theoretically, and the structural parameters of the sensor are determined by simulation analysis. The size of the miniaturized vibration sensor is 27 mm × 11 mm × 22 mm with a mass of only 5 g. Experimental results show that the sensor can accurately acquire vibration signals. The sensitivity is about 12 pm/g in the flat range of 0-800 Hz, and the natural frequency is 1525 Hz. Moreover, the transverse interference of the sensor is less than 3.5%, and its dynamic range is up to 86 dB. The sensor can be suitable for mechanical vibration measurement in the mid-high frequency range, which has special requirements for size, quality, and distributed measurement.