摘要
针对传统外调制光频域反射(OFDR)系统空间分辨率较差的问题,提出了基于IQ调制OFDR系统的方法。分析了OFDR系统基本原理及IQ调制扫频原理,采用IQ调制器调制稳频激光器产生线性扫频光,建立了基于IQ调制的OFDR系统仿真模型;通过改变局部后向散射光相位以模拟待测温度或应变变化,并提出差分FFT解调算法实现对待测参量的快速定位检测。仿真结果表明,模型可以准确检测与定位施加在传感光纤上的模拟待测参量,并在传感距离为100m长的光纤上实现了0.23m的空间分辨率。研究证明,该系统优化了空间分辨率,降低了解调算法复杂度,提高了参量检测准确度,从而为光频域反射技术在短距离高空间分辨率应变、温度等参量检测方面的应用提供理论依据和测量方法。
Aiming at the problem of low spatial resolution in conventional optical frequency domain reflectometry(OFDR) systems utilizing external modulation laser source, a method of an OFDR system based on IQ modulation tunable laser source(TLS) is proposed. The principles of the basic OFDR system and the IQ modulated frequency sweeping laser source are analysed. The frequency stabled incident laser is modulated utilizing IQ modulator to generate frequency sweeping light signal. The simulation model of OFDR system based on IQ modulation is established. The temperature or strain changes are generated on the fiber under test(FUT) by altering the phase on the local backscattering light. A differential FFT demodulation method is proposed to detect the position of parameter variation with a high speed. The simulation results demostrate that the system is able to sense and locate the simulated parameter changes on FUT with high accuracy, and a 0.23 m spatial resolution with 100 m sensing range is achieved. The research demostrates that the system optimizes the spatial resolution, reduces the complexity of the demodulation algorithm and improves the parameter sensing accuracy, which provides theoretical basis and measurement methods for OFDR applications in short range strain and temperature sensing with high spatial resolution.
作者
延敏
白清
梁昌硕
王宇
刘昕
靳宝全
YAN Min;BAI Qing;LIANG Changshuo;WANG Yu;LIU Xin;JIN Baoquan(Key Laboratory o£Advanced Transducers and Intelligent Control System of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China)
出处
《光学技术》
CAS
CSCD
北大核心
2020年第6期696-701,共6页
Optical Technique
基金
山西省青年科技研究基金(201901D211072)。
关键词
光频域反射
IQ调制器
参量检测
光纤传感
线性扫频
optical frequency domain reflection
IQ modulator
parameter detection
optical fiber sensing
linear sweep
