基于分布布拉格反射光纤激光器的高灵敏度微振动传感器  

High Sensitivity Micro-Vibration Sensor Based on Distributed Bragg Reflector Fiber Laser

作　　者：鲁文高[1,2] 孙琪真[1,2] 沃江海[1,2] 王贺[1,2] 刘德明[1,2] 

机构地区：[1]华中科技大学光学与电子信息学院,湖北武汉430074 [2]华中科技大学下一代互联网接入系统国家工程实验室,湖北武汉430074

出　　处：《光学学报》2014年第7期283-288,共6页Acta Optica Sinica

基　　金：国家自然科学基金(61275004;61290315);国防科工局民用航天预研基金;华中科技大学国防自主创新基金

摘　　要：设计并验证了一种基于分布布拉格反射(DBR)光纤激光器的高灵敏度微振动传感器。该传感器结构采用常见的质量块弹簧系统,质量块由于重力作用对DBR激光器的谐振腔产生侧向压力。当测试平台发生振动时,谐振腔所受到的侧向压力发生变化,导致激光器输出的两正交偏振模式产生的拍频信号改变。通过高速光电探测器和多通道数据采集平台对拍频信号进行采集,使用LabVIEW编程对采集信号进行处理,实现了对振动加速度信号的实时监测。理论分析与实验结果表明,该传感器具有极高的加速度灵敏度,对于单位重力加速度g其灵敏度达吉赫兹量级,能检测到微弱的振动信号。相较于传统光纤振动传感器而言,该传感器将光谱分析转化为频谱分析,使信号的采集与解调更加简单,且获得了更高的灵敏度。进一步分析表明,此结构在微重力环境下进行测量也是可行的,因此,在航空飞行器关键部件的微振动测量中有较大的应用潜力。A high sensitivity micro-vibration senor based on distributed Bragg reflector （DBR） fiber laser is designed and demonstrated. The sensor structure uses common mass-spring system. Due to gravity, the DBR laser cavity is subjected to lateral pressure caused by the mass. Because the lateral pressure that the laser cavity suffers changes when the testing platform is vibrating, the beat frequency generated by two orthogonally polarized modes of the laser output changes. By the high-speed photodetector and multi-channel data acquisition platform, the beat frequency signal is collected. The signal can be dealed with through the LabVIEW programming and the real-time monitoring of the vibration acceleration signal is achieved. Theoretical analysis and experimental results show that, the sensor has a very high acceleration sensitivity, which is up to gigahertz for an acceleration of gravity g, and can detect very weak vibration signal. Compared with the traditional optical fiber vibration sensors, this sensor convert optical spectrum analysis to frequency spectrum analysis, which makes the signal acquisition and demodulation easier, and obtains a higher sensitivity. Further analysis shows that the measurement of this structure in the micro-gravity environment is also feasible. Therefore, it has great potential in the micro-vibration measurements of key components of aerospace craft.

关 键 词：传感器 振动传感器 高灵敏度 分布布拉格反射光纤激光器 拍频 

分 类 号：O436[机械工程—光学工程]