Abstract Fiber-optic interferometric sensor arrays are very attractive for many applications. One of the common used interrogation approaches for fiber-optic sensor arrays is the path matched differential interferometry (PMDI). It allows to interrogate a large number of multiplexed fiber-optic sensors by using an auxiliary compensation interferometer (CIF). This approach with using the phase modulator allows to implement the phase-generated carrier demodulation for multiplexed fiber-optic sensors. However, this approach has the significant disadvantage, which is that environmental vibroacoustic impacts on the CIF produce undesirable phase signals from the sensor array. It leads to increasing the noise floor level of the measuring system. In this paper the development methodology and results of the experimental investigation of the passive vibroacoustic isolation system for the CIF in the PMDI-based fiber-optic interferometric sensor are presented. The proposed isolation system is implemented by using acoustic absorbing layers and the special mechanical suspension system for the CIF mounted in the single rack unit. It is shown that the proposed approach for the CIF isolation allows to reduce its sensitivity to vibroacoustic impacts by up to 30 dB in the frequency range up to 500 Hz. It is also demonstrated that potting of the CIF fiber-optic components reduces its isolation efficiency by an average value of 8.3 dB in the considered frequency range, that is not applicable for interferometric sensors. The presented methodology and obtained results might be used in PMDI-based fiber-optic interferometric sensors to improve their performance characteristics.

中文翻译：

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基于路径匹配差分干涉测量的光纤传感器无源振动声隔离系统的开发

摘要 光纤干涉传感器阵列对许多应用非常有吸引力。光纤传感器阵列常用的询问方法之一是路径匹配差分干涉法 (PMDI)。它允许使用辅助补偿干涉仪 (CIF) 询问大量多路复用光纤传感器。这种使用相位调制器的方法允许实现多路复用光纤传感器的相位生成载波解调。然而，这种方法有一个明显的缺点，即环境振动声对 CIF 的影响会产生来自传感器阵列的不希望有的相位信号。它会导致测量系统的本底噪声水平增加。在本文中，介绍了基于 PMDI 的光纤干涉传感器中 CIF 无源振动声隔离系统的开发方法和实验研究结果。建议的隔离系统是通过使用吸音层和安装在单个机架单元中的 CIF 的特殊机械悬挂系统来实现的。结果表明，所提出的 CIF 隔离方法允许在高达 500 Hz 的频率范围内将其对振动声影响的敏感性降低高达 30 dB。还证明了 CIF 光纤组件的灌封在所考虑的频率范围内将其隔离效率降低了 8.3 dB 的平均值，这不适用于干涉传感器。