High-Frequency Optical Fiber Bragg Grating Accelerometer

Abstract

Fiber Bragg grating (FBG)-based accelerometer technology receives much attention from various research communities. In this paper, we investigated an FBG accelerometer with high resonant frequency for mechanical equipment. A special steel tube-mass block elastic structure with two FBGs embedded has been designed for axial vibration sensing. The steel tube was fixed on the mass block and threaded pipe in the sensor by sintering and pre-stretched to serve as a spring element. Then, a sensor prototype has been manufactured and fully tested. Experimental results show that the sensor provides a high resonant frequency of 3806 Hz with a wide flat response region up to 1200 Hz, which is consistent with the theoretical value of 3993 Hz. The sensitivity of the sensor is 4.01 pm/g with a fitting linear correlation coefficient of 0.9997. Temperature change test and excitation test along the working direction and transverse direction have been carried out, which confirmed excellent anti-interference ability and temperature compensation ability of the sensor.