Influences of pulse parameters on the performance of double-pulse φ-OTDR

作者：Zhong, Xiang^*; Chen, Xiaoshan; Cao, Hanyu; Deng, Huaxia^*; Ren, Jie; Xiao, Xingzhi; Sun, Yu; Ma, Mengchao

来源：Optics and Laser Technology, 2023, 161: 109128.

DOI：10.1016/j.optlastec.2023.109128

• Demodulation range
• Double probe pulses
• Phase-sensitive optical time domain
• refractometry
• Spatial resolution

In the past decade, an increasing number of studies of double-pulse 0-OTDR systems have been reported, but so far, there are no studies specifically analyzing the influences of double pulses on system performance. In this paper, we construct a theoretical model of the double-pulse 0-OTDR system, analyze the interference process of the system theoretically, and make conjectures on spatial resolution and demodulation range. On the basis, we build a double-pulse 0-OTDR experimental setup based on Sagnac balanced interferometer. The feasibility of the proposed theory is verified by experiments altering the probe pulse parameters and localizing two-point disturbances at different frequencies. The results also indicate when pulse width is greater than the pulse interval, this system offers more accurate positioning capabilities and a continuous demodulation range with high fidelity. The conclusions provide a reference for the selection of appropriate double-pulse parameters for similar systems, and the theoretical model offers a methodological suggestion for exploring other types of double pulses or even multi-pulse systems.

• 单位
  中国科学院