光学学报, 2017, 37 (1): 0106001, 网络出版: 2017-01-13
瑞利布里渊光时域分析系统传感性能的提升方法 下载: 584次
Performance Improvement Method of Rayleigh Brillouin Optical Time Domain Analysis System
光纤光学 布里渊光时域分析 信噪比 单端结构 瑞利散射 受激布里渊散射阈值 fiber optics Brillouin optical time domain analysis signal-to-noise ratio single-end structure Rayleigh scattering stimulated Brillouin scattering threshold
摘要
将多波长激光光源技术引入瑞利布里渊光时域分析系统, 其中抑制载波的微波调制多波长脉冲基底1阶边带会在传感光纤中产生多波长背向瑞利散射; 将该散射光作为探测光与多波长传感脉冲发生受激布里渊散射(SBS)作用, 可有效地提高光纤SBS阈值和SBS作用效率, 进而提高系统信噪比和布里渊频移的测量精度。分析了相位调制器产生多波长激光光源的原理以及利用电光强度调制器产生作为探测光的多波长斯托克斯和反斯托克斯激励光的原理, 建模分析了多波长瑞利布里渊光时域分析系统原理, 给出了系统信噪比与波长数关系的表达式; 搭建了单波长和三波长光纤SBS阈值测量系统及瑞利布里渊光时域分析系统, 测量了光纤的SBS阈值和系统性能。实验结果表明, 当单波长与三波长瑞利布里渊光时域分析系统的传感脉冲宽度为100 ns, 峰值功率为100 mW, 单个波长的脉冲基底功率约为1.3 mW, 传感光纤长度为2.4 km时, 三波长较单波长系统的光纤SBS阈值和信噪比分别提高了3倍和2.83倍, 在2 km光纤内布里渊频移波动由33.4 MHz降至15.6 MHz。
Abstract
The technique of multi-wavelength laser source is introduced into Rayleigh Brillouin optical time domain analysis system, in which multi-wavelength Rayleigh back-scattering generated by the 1st-order side-band of suppressed carrier microwave-modulated multi-wavelength pulse base is used as probe light to interact with the multi-wavelength sensing pulse through stimulated Brillouin scattering (SBS). The interaction can effectively improve the fiber SBS threshold, SBS interaction efficiency, and measurement precision of signal-to-noise ratio and Brillouin frequency shift. The generation principle of the multi-wavelength laser source by phase modulator and the exciting source of multi-wavelength Stokes light and anti-Stokes light used as probe light in the system by electro-optic intensity modulator is analyzed. The multi-wavelength Rayleigh Brillouin optical time domain analysis system is characterized by modeling analysis, in which the relationship between the signal-to-noise ratio and the wavelength number is achieved. Then a fiber SBS threshold measurement system and a Rayleigh Brillouin optical time domain analysis system using single-wavelength and three-wavelength laser sources are designed and the fiber SBS threshold and the system performance are tested. Experimental results show that when the fiber length is 2.4 km, the sensing pulse is with a width of 100 ns and a power of 100 mW, and the pulse base is with a power about 1.3 mW for each wavelength component in the single-wavelength and the three-wavelength systems, the fiber SBS threshold and signal-to-noise ratio in three-wavelength sensing system are approximately to be as high as 3 times and 2.83 times than that in single-wavelength sensing system, respectively. And within 2 km fiber length, the Brillouin frequency shift fluctuation decreases from 33.4 MHz in single-wavelength sensing system to 15.6 MHz in three-wavelength sensing system.
李永倩, 张立欣, 李晓娟, 杨润润. 瑞利布里渊光时域分析系统传感性能的提升方法[J]. 光学学报, 2017, 37(1): 0106001. Li Yongqian, Zhang Lixin, Li Xiaojuan, Yang Runrun. Performance Improvement Method of Rayleigh Brillouin Optical Time Domain Analysis System[J]. Acta Optica Sinica, 2017, 37(1): 0106001.