Chang Tianying, Wang Zhongmin, Yang Yue, Zhang Yaolu, Zheng Zhifeng, Cheng Liyao, Cui Hong-Liang
Opt Express. 2020 Mar 2;28(5):6102-6122. doi: 10.1364/OE.385703.
A high-sensitivity ultralow-frequency fiber optic interferometric seismometer using phase feedback control is proposed and demonstrated. The principle of sensitivity improvement using feedback is described, and the characteristics of the seismometer, including the ultralow-frequency vibration sensing with Michelson interferometer with and without feedback control, are analyzed in terms of the amplitude response and phase response. The phase feedback control loop is designed and implemented, and higher sensitivity for very low frequency vibration is achieved. The efficacy of the new approach is demonstrated experimentally, showing that the weak vibration signal originally buried in noise can be observed unambiguously.
提出并演示了一种采用相位反馈控制的高灵敏度超低频光纤干涉地震仪。描述了利用反馈提高灵敏度的原理，并从幅度响应和相位响应方面分析了地震仪的特性，包括采用有反馈控制和无反馈控制的迈克尔逊干涉仪进行超低频振动传感的特性。设计并实现了相位反馈控制环路，实现了对极低频振动的更高灵敏度。通过实验证明了该新方法的有效性，表明原本淹没在噪声中的微弱振动信号能够被清晰地观测到。
