A record long external-disturbance detection distance of 140 km without employing optical amplifiers in the fibre line is demonstrated by a phase-sensitive optical time-domain reflectometer (Φ-OTDR) using a fibre section with inscribed chirped fibre Bragg gratings (CFBGs). This solution provides simultaneous operation of Φ-OTDR with a standard single-mode fibre at a distance of up to 100 km and with a CFBG fibre section located from the fibre line input point by at least 140 km.

中文翻译：

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通过使用带有chi光栅的光纤来扩展相敏光时域反射仪的工作范围

相位敏感的光时域反射仪（Φ-OTDR）使用带有内切chi光纤布拉格光栅（CFBGs）的光纤段，证明了在光纤线路中未使用光放大器的140 km的长外部干扰检测距离。该解决方案可同时使用Φ-OTDR和标准单模光纤（最大距离为100 km）以及CFBG光纤段（距光纤线输入点至少140 km）进行同时操作。