INESC Porto, Porto, Portugal.
Opt Lett. 2013 Mar 15;38(6):872-4. doi: 10.1364/OL.38.000872.
Phase-sensitive optical time-domain reflectometry (φOTDR) is a simple and effective tool allowing the distributed monitoring of vibrations along single-mode fibers. We show in this Letter that modulation instability (MI) can induce a position-dependent signal fading in long-range φOTDR over conventional optical fibers. This fading leads to a complete masking of the interference signal recorded at certain positions and therefore to a sensitivity loss at these positions. We illustrate this effect both theoretically and experimentally. While this effect is detrimental in the context of distributed vibration analysis using φOTDR, we also believe that the technique provides a clear and insightful way to evidence the Fermi-Pasta-Ulam recurrence associated with the MI process.
相位敏感光时域反射计（φOTDR）是一种简单而有效的工具，可实现沿单模光纤对振动的分布式监测。在本信中，我们表明调制不稳定性（MI）会在常规光纤中的长距离 φOTDR 中引起与位置相关的信号衰落。这种衰落会导致在某些位置记录的干涉信号完全被屏蔽，从而导致这些位置的灵敏度损失。我们从理论和实验两个方面说明了这一效应。虽然在使用 φOTDR 进行分布式振动分析的背景下，这种效应是不利的，但我们也认为该技术为证明与 MI 过程相关的费米-帕斯塔-乌伦姆重现提供了一种清晰而有见地的方法。
