Self-heterodyne φ-OTDR system with free multi-spatial resolution

US11860008B2 · kind B2 · utility

Assignee

• Nanjing University · CN

Inventors

• Yixin Zhang · Dresden, DE
• Jinyu Song · Nanjing, CN
• Xuping Zhang · Nanjing, CN
• Zhewen Ding · Nanjing, CN
• Shuai Tong · 安丰镇, CN
• Shun Wang · 安丰镇, CN
• Feng Wang · Nanjing, CN

Key dates

• Filing date: May 6, 2022
• Grant date: Jan 2, 2024
• Expiry date: May 6, 2042

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/35361
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A self-heterodyne phase-sensitive optical time domain reflectometry (φ-OTDR) system with a free multi-spatial resolution includes a narrow linewidth laser source, a 1×3 fiber-optic coupler, three acousto-optic modulators (AGMs), a 3×1 fiber-optic coupler, two time-delay fibers, an erbium-doped fiber amplifier (EDFA), a circulator, a photodetector, an electrical amplifier, three filters, a data acquisition card, a pulse signal generator, and a driver module. A plurality of acousto-optic modulators using the same driver are used to couple probe light with different pulse intervals and different frequency shifts and then inject the probe light into a fiber, such that a self-heterodyne detection structure with a multi-spatial resolution is implemented, which suppressed optical background noise such as coherent fading noise, phase noise introduced by a frequency drift of a light source, and pseudo-random noise (PRN).