Noise Analysis and Performance Improvement of a MEMS Fabry-Pérot Seismic Accelerometer
Minghui Zhao, Yonghong Qi, Xiaopeng Zhang, Bo Li, Zhuangde Jiang, Xueyong Wei
Abstract
MEMS accelerometers based on the optical interference technique play an important role in seismic wave detection due to their high resolution, strong electromagnetic stability, and low cost. This paper reports a MEMS Fabry-Pérot seismic accelerometer. The working principle and transfer function were established to introduce the accelerometer. Noise sources that contribute to the output of the accelerometer were analyzed and predicted. To improve the performance of the accelerometer, the active temperature compensation, the appropriate laser driving current selection, and the laser modulation-demodulation technologies were adopted to reduce the noise. Experimental results show that the noise floor of the accelerometer was decreased from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$11 ~\mu \text{g}/\surd $ </tex-math></inline-formula> Hz@1 Hz to 330 ng/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\surd $ </tex-math></inline-formula> Hz@1 Hz.