%0 Journal Article %T 光纤超声传感系统3×3耦合器输出信号的影响因素研究</br>Research on the factors affecting the output signal of 3×3 coupler in optical fiber ultrasonic sensing system %A 陈家熠 %A 吴先梅 %A 吕文瀚 %A 程茜 %J 声学技术 %D 2018 %R 10.16300/j.cnki.1000-3630.2018.06.008 %X 光纤超声传感单位通常使用3×3耦合器作为核心干涉部件,其输出信号往往变化范围大、稳定性差,为了分析3×3耦合器输出信号产生不同现象的原因,开展了3×3耦合器输出信号的影响因素研究。应用干涉理论,分析了声信号和环境噪声对3×3耦合器输出信号稳定性的影响。数值计算结果与实验结果表明:声信号与环境噪声共同调制了干涉仪的相位,环境噪声使得3×3耦合器输出信号稳定性差;通过增大声信号幅值,使其引起的干涉仪相位幅值大于π rad,此时3×3耦合器输出信号的稳定性增强。</br>Optical fiber ultrasonic sensors usually use 3×3 coupler as their core interferometer. The output signals of 3×3 coupler often vary in a wide range and have poor stability. In order to understand why different phenomena happen in the output signals, the factors affecting the output signal of 3×3 coupler are studied. By using interference theory, the effects of acoustic signal and ambient noise on the stability of output signal of the 3×3 coupler are analyzed. Both simulation and experimental results show that a stable output signal can be obtained when the amplitude of acoustic signal is relatively large. %K 光纤超声传感|3× 3耦合器|干涉理论< %K /br> %K optical fiber ultrasonic sensor|3× 3 coupler|interference theory %U http://sxjs.cnjournals.cn/ch/reader/view_abstract.aspx?flag=1&file_no=20180608&journal_id=sxjs