Sagnac干涉式光纤声传感器及其定位技术研究

【作者】 吴东方；

【导师】 华中一； 贾波；

【作者基本信息】 复旦大学 ， 物理电子学， 2008， 博士

【摘要】 光纤声传感器具有灵敏度高、抗电磁干扰等突出优点,受到了广泛的重视与应用。本文在Sagnac干涉式光纤声传感器的研究基础上,提出了一种新型的Saganac干涉型光纤麦克风模型,从理论和实验两方面对光纤麦克风进行了研究,并对研制的光纤麦克风进行了性能测试,主要指标达到了预期的功能。同时,将光纤干涉技术与光纤分布式传感技术结合而成的干涉型分布式光纤声源定位技术,对当前干线、管道破坏行为预警具有重要的意义。光纤干涉型的分布式声传感系统由于基于相位调制原理,其高灵敏度的传感特性已为大家所公认,但针对高精度的定位技术还有待进一步深入研究。在对传统Saganc干涉仪结构改进的基础上,提出了一种单轴式的Sagnac干涉型光纤声传感器的定位技术,以解决Sagnac光纤干涉仪环状结构对其应用的限制。在上述理论基础上,设计了能够实现声源定位的分布式光纤声传感器系统。通过相位解调、功率谱分析、小波去噪等技术手段,系统的定位精度基本达到了预期目标。鉴于声源预警、定位技术的巨大需求,基于Saganac结构的光纤分布式声传感系统定位技术的研究,不仅具有非常高的理论可行性,而且具有重大的科学价值和潜在的社会经济效益。更多还原

【Abstract】 Fiber-optic acoustic sensors have received more and more attentions because of its excellences such as high sensitivity and anti-EMI. A novel fiber-optic microphone is introduced in this paper Based on Sagnac interference technology. The fiber-optic microphone is investigated theoretically and experimentally. A designed fiber-optic microphone system is realized and tested.Optical fiber acoustic sensing system which combines the fiber interference and fiber distributed sensing technology is one of the most ideal early-alarm technologies of communication fiber and pipe destruction. Based on the interferometer, the distributed fiber interferometer acoustic sensing system is regarded to be capable of any potential destruction of the fiber path. But its high precision locating technology should be developed further.Sagnac interferometer is converted into linear structure by using a new structure , which can overcome the loop shortcoming of traditional optical fiber Sagnac interferometer.This device was analyzed in theory and sound vibration was studied as an example in experiment. The experimental result accords with the theoretic analysis and the location accuracy is reach the target through signal treatment method such as phase demodulation, power spectrum and wavelet denoising , which shows that the novel device can realize the detection and location of the sound signal source .Because of the great needs of early-alarm and location of sound signal source, the research on this field has not only great science value but also potential social and economic benefits.更多还原