Analysis of the natural frequency and phase sensitivity of an optical fiber accelerometer coated with a rigid package

Abstract

The operation frequency band and the output signal-to-noise ratio of the optical fiber accelerometer are decided by the natural frequency and phase sensitivity of the accelerometer, respectively. Until now, existing theoretical models have been incapable of analyzing the performance of the accelerometer coated with the rigid package. In this paper, an improved model is presented to explain the interreaction between the rigid package and the mass spring assembly inside. The natural frequency and phase sensitivity are affected by both the package mass and the damping of the surrounding medium. With the increase of the package mass, the natural frequency becomes lower and the phase sensitivity becomes higher. The damping of the surrounding medium induces the additional mass added on the package, which increases with the density of the medium. Further, the performance of the three-component vector accelerometer is analyzed by using the improved model. Experiments on the unpackaged and packaged accelerometers in different surrounding mediums indicate that our method is efficient. The improved model is also useful for the traditional piezoelectric accelerometer.