Technical and Experimental Study of Fiber Bragg Grating Vibration Detection Based on Matching Demodulation Method

Compared to the conventional vibration sensor, fiber Bragg grating (FBG) vibration sensor has some more advantages of good ingenious, high sensitivity, interference free of electronic-magnetism, adapt to long-term monitoring, etc. Fiber Bragg grating vibration detection is introduced and its mechanical model of measuring acceleration is established in the paper. A scheme of single point matching FBG demodulation is designed and demonstrated to measure low frequency vibration in construction, rock and soil engineering monitoring and so on. The demodulation of FBG detection is simulated and achieved via mathematical method and experiments. Low frequency vibration signal is modulated sine wave signal, which is analyzed through matching demodulation detection and signal spectrum. The experimental results are in agreement with the simulation, which proves that this method can detect low frequency vibration and is feasible.