A Scheme for Long-distance High-resolution Detection of Fiber Link

Abstract

Aiming at the problem of low spatial resolution of Optical Time Domain Reflectometer (OTDR) in long distance optical fiber link detection, this paper proposes a new scheme of Linear Frequency Modulation (LFM) -Golay OTDR. The scheme improves the dynamic range and spatial resolution of the OTDR by generating LFM signals to modulate optical signals and generating Golay sequence signals to modulate LFM optical signals. The experimental results show that the spatial resolution of the LFM-Golay OTDR can reach resolution of 0.22 m in the optical fiber link under test with a length of 200 km. Under the conditions of same setting parameters, the dynamic range is increased by about 15 dB compared with single pulse OTDR, and the dynamic range of LFM-Golay OTDR is about 6 dB higher than Golay OTDR and LFM OTDR.

Keywords

• otdr
• lfm
• golay code
• spatial resolution
• dynamic range