摘要
受光纤中声学声子10 ns的寿命的影响,传统布里渊光时域分析(BOTDA)传感器往往不能做到1 m以内的空间分辨率。利用差分脉冲对(DPP)技术可以突破该限制,实现更高的空间分辨率。但是传统的DPP技术存在测量时间长、差分信号间同步难度高和信噪比低等问题。本文提出一种基于布里渊增益-损耗效应的编码DPP-BOTDA系统,通过将处于斯托克斯频率和反斯托克斯频率的泵浦脉冲光同步注入光纤,利用散射光的布里渊增益-损耗效应在光路上差分,解决了信号间的同步问题,并且测量时间只需要传统DPP技术的一半。还分析了传感系统中掺铒光纤放大器增益特性对脉冲序列解码结果的影响,对增益不均匀条件下的编码增益进行了理论计算。实验结果表明,该系统可以实现50 cm的空间分辨率,与传统的单脉冲DPP-BOTDA系统相比,信噪比提高了3 dB。
The spatial resolution of traditional Brillouin optical timedomain analysis(BOTDA)sensor is often unable to achieve the spatial resolution within 1 m due to the influence of 10 ns acoustic phonon lifetime in optical fibers.The differential pulse pair(DPP)technique can avoid this limitation and obtain higher spatial resolution.However,the traditional DPP technique has problems,such as long measurement time,high difficulty in synchronization,and low signaltonoise ratio.In this paper,we propose a coded DPPBOTDA system based on the Brillouin gainloss effect.the pump pulse light at Stokes frequency and antiStokes frequency is synchronously injected into the optical fiber,and the Brillouin gain loss effect of the scattered light is used to differentiate on the optical path to solve the synchronization problem between signals,and the measurement time is half of the traditional DPP method.The influence of the gain characteristics of an erbiumdoped fiber amplifier in the sensing system on the decoding results of pulse sequences is analyzed,and the coding gain under the condition of uneven gain is calculated theoretically.The experimental results show that the system can obtain a spatial resolution of 50 cm with a signaltonoise ratio improvement of 3 dB compared with the traditional singlepulse DPPBOTDA system.
作者
刘钦
黄劲
梁浩
程凌浩
Liu Qin;Huang Jin;Liang Hao;Cheng Linghao(Institute of Photonics Technology,Jinan University,Guangzhou 510632,Guangdong,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2023年第9期417-422,共6页
Laser & Optoelectronics Progress
基金
国家自然科学基金(61875246、62075086)。
关键词
传感器
光纤传感器
布里渊散射
差分脉冲对
光脉冲编码
sensors
fiber sensor
Brillouin scattering
differential pulsewidth pair
optical pulse coding
