Author Affiliations
Abstract
1 Key Lab of Advanced Transducers and Intelligent Control Systems, Ministry of Education and Shanxi Province, Taiyuan 030024, China
2 Institute of Optoelectronic Engineering, College of Physics & Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
3 Fiber Optics Group, Department of Physics, University of Ottawa, Ottawa K1N 6N5, Canada
To obtain high spatial resolution over a long sensing distance in Brillouin optical correlation domain reflectometry (BOCDR), a broad laser spectrum and high pump power are used to improve the signal-to-noise ratio (SNR). In this Letter, we use a noise-modulated laser to study the variation of the Brillouin spectrum bandwidth and its impact on the coherent length of BOCDR quantitatively. The result shows that the best spatial resolution (lowest coherent length) is achieved by the lowest pump power with the highest noise-modulation spectrum. Temperature-induced changes in the Brillouin frequency shift along a 253.1 m fiber are demonstrated with a 19 cm spatial resolution.
060.2370 Fiber optics sensors 060.4080 Modulation 120.5820 Scattering measurements Chinese Optics Letters
2017, 15(8): 080603
1 新型传感器与智能控制教育部重点实验室， 山西 太原 030024
2 太原理工大学物理与光电工程学院光电工程研究所， 山西 太原 030024
为提高分布式光纤拉曼测温系统的测量速度和测量准确度，提出了一种自补偿光纤损耗及光纤色散的温度解调方法，并进行了实验验证。该方法对斯托克斯与反斯托克斯后向散射信号进行了损耗修正，避免了测温前对整条传感光纤进行定标处理的过程，减小了系统的运行时间；采用色散补偿平移算法对斯托克斯后向散射信号的位置进行修正，获得了与反斯托克斯后向散射信号相同位置处的斯托克斯后向散射信号的强度，降低了光纤色散对温度解调的影响，提高了系统的测温准确度。实验结果表明，当光纤传感距离为5.8 km时，温度波动由9.01 ℃下降到0.57 ℃，测温准确度由5.50 ℃优化至0.87 ℃。
光通信 分布式光纤传感 拉曼测温 光纤色散补偿 光纤损耗
