We demonstrate the detection of speech signals and footsteps through a novel polarization-multiplexed coded differential-phase OTDR (optical time domain reflectometry) interrogation of standard telecom fibers in different configurations. We assess the sensitivity to audio signals by measuring the induced phase variation with respect to the sound pressure level of the perturbation, and manage to detect acoustic signals with high reliability. Further experiments are performed using an installed fiber cable showing the ability to track footsteps in an indoor scenario. These experiments pave the way for numerous applications of Distributed Acoustic Sensing (DAS) where a high sensitivity is required.

中文翻译：

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用于声学信号检测的高灵敏度差分相位 OTDR


我们演示了通过对不同配置的标准电信光纤进行新颖的偏振复用编码差分相位 OTDR（光时域反射计）询问来检测语音信号和脚步声。我们通过测量相对于扰动声压级的感应相位变化来评估对音频信号的敏感性，并设法以高可靠性检测声信号。使用已安装的光缆进行了进一步的实验，显示了在室内场景中跟踪脚步的能力。这些实验为需要高灵敏度的分布式声学传感 (DAS) 的众多应用铺平了道路。