摘要
搭建基于3×3耦合器的非平衡马赫-曾德尔(M-Z)干涉系统,将3×3耦合器解调与相位载波结合,通过引入载波调节M-Z干涉仪的输出相位进行动态解调。载波信号为频率2 kHz,电压为0、2、6、10、16 V的余弦信号,通过Throlabs光学能量计测量干涉仪输出功率随时间变化曲线,针对3×3耦合器分光比不均等为1∶1∶1,即相位差不为120°,将输出干涉光采用经验模态分解并构建带通滤波器进行去噪,将处理后的信号用最小二乘法进行李萨如曲线拟合,求得椭圆具体参数,利用反正切函数求解相位差。得出电压相移系数以及电压波长偏移系数分别为0.7577(°/V)、0.7258×10^(-3)(nm/V),在MATLAB中拟合一阶线性曲线,拟合优度R^(2)在0.98以上。最后将此解调系统应用于光纤光栅串(FBG)的应力负载试验并与微光光学解调仪(MOI)相对比,结果表明本系统准确度高,对1560 nm的FBG解调效果较MOI更佳。
An unbalanced M-Z interference system based on the 3×3 coupler is established.Combining the 3×3 coupler demodulation with the phase carrier,the output phase of the M-Z interferometer is dynamically demodulated by introducing carrier to adjust the output phase.The carrier wave is a cosine signal with a frequency of 2 kHz and a voltage of 0,2,6,10 and 16 V.The output power curve of the interferometer with time is measured by the Throlabs optical energy meter.For the unequal splitting ratio of 3×3 coupler with 1∶1∶1,the phase difference is not 120°,the output interference light is decomposed by empirical mode,and a band-pass filter is constructed for denoising.The processed signal is fitted with Lissajous curve by the least square method to obtain the specific parameters of ellipse.The arctangent function is used to solve the phase difference.Finally,the voltage phase shift coefficient and the voltage wavelength shift coefficient are 0.7577(°/V)and 0.7258×10^(-3)(nm/V),respectively.The first-order linear curve is fitted in MATLAB,and the goodness of fit R^(2)is more than 0.98.Finally,the demodulation system is applied to the stress load test of fiber Bragg grating(FBG)strings and compared with the micron optics(MOI)demodulation.The results show that the accuracy of this system is high,and the FBG demodulation effect at 1560 nm is better than MOI.
作者
王彦
蒋超
朱伟
汪俊亮
徐浩雨
Wang Yan;Jiang Chao;Zhu Wei;Wang Junliang;Xu Haoyu(School of Electrical and Information Engineering,Anhui University of Technology,Ma′anshan 243000,China)
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2023年第2期84-92,共9页
Chinese Journal of Scientific Instrument
基金
安徽省科技重大专项(201903a05020029)资助
关键词
光纤光栅
3×3耦合
M-Z干涉
压电陶瓷
相位解调
fiber bragg grating
3×3 coupler
M-Z interference
piezoelectric ceramics
phase demodulation
作者简介
通信作者:王彦,教授,硕士生导师。2008年获得南京航空航天大学智能监测与控制专业工学博士,现任安徽工业大学电气与信息工程学院教授,主要研究方向为智能监测与控制、光电测试技术、结构健康监测。E-mail:wangyan@ahut.edu.cn
