基于光纤光栅的时分复用传感阵列相位噪声研究  

Background Phase Noise of Interferometric TDM Sensing Array Based on Fiber Bragg Grating

作　　者：尚凡 戚悦 马丽娜[1] 蒋鹏 陈羽[1] 王俊[1] 熊水东[1] Shang Fan;Qi Yue;Ma Lina;Jiang Peng;Chen Yu;Wang Jun;Xiong Shuidong(College of Meteorology and Oceanography,National University of Defense Technology,Changsha,Hunan 410073,China)

机构地区：[1]国防科技大学气象海洋学院,湖南长沙410073

出　　处：《光学学报》2021年第13期87-97,共11页Acta Optica Sinica

基　　金：国家自然科学基金(61901488)。

摘　　要：针对采用相位生成载波(PGC)调制解调方案的光纤光栅时分复用(TDM)传感系统,研究传感阵列结构和调制解调参数对系统相位噪声的影响。理论分析结果表明,阵列的结构设计会制约系统调制解调参数的设计与选取,而且因光纤光栅传感系统中需采用偏振调制手段来抑制偏振诱导信号衰落,当时分复用数量越多和单基元传感光纤长度越长时,系统调制解调频率的上限越低。仿真分析PGC调制解调算法中的高频混叠效应,结果表明调制频率越小,系统的本底相位噪声越大。实验搭建4套不同设计结构的干涉型光纤光栅时分复用传感阵列,PGC调制频率分别为6,10,16,50 kHz。实验测得4套系统在1 kHz频点处,第一时分复用通道相位噪声分别为-93,-96,-98和-99 dB/Hz1/2,与理论分析结果吻合。For a fiber-grating time-division multiplexing(TDM) sensing system adopting the phase-generated carrier(PGC) modulation and demodulation schemes, the influence of the structure of the sensor array and the modulation and demodulation parameters on the system phase noise is investigated. The theoretical analysis results show that the array will constrain system structure design of modem design and selection of parameters, and by using polarization modulation in the fiber Bragg grating sensing system means to suppress the induced polarization signal fading. When the number of time-division multiplexing is larger, the system frequency modulation demodulation of the lower limit. The simulation analysis of the high-frequency aliasing effect in the PGC modulation and demodulation algorithms show that the smaller the modulation frequency, the greater the background phase noise of the system. In the experiment, four sets of interferometric fiber Bragg grating time-division multiplexing sensor arrays with different design structures are constructed. The PGC modulation frequencies are 6, 10, 16, and 50 kHz. The experimental results show that the phase noises of the first time-division multiplexing channel for the four systems at the frequency of 1 kHz, are-93,-96,-98, and-99 dB/Hz1/2, respectively, which are consistent with the theoretical analysis results.

关 键 词：光纤光学 光纤传感 光纤光栅 相位噪声 相位生成载波 

分 类 号：O436.1[机械工程—光学工程]