基于法拉第效应的正交双频光纤激光磁场传感器的敏感特性研究

发布时间：2018-01-08 10:21

本文关键词：基于法拉第效应的正交双频光纤激光磁场传感器的敏感特性研究　出处：《暨南大学》2015年硕士论文　论文类型：学位论文

【摘要】：磁场的测量在各个领域如导航、电流检测、空间和地球物理研究等都有广泛的应用。全光纤磁场传感器因其具有重量轻、体积小和带宽窄等优势而备受瞩目。光纤磁场传感器是以光纤器件作为敏感元件,通过借助相位、偏振态、幅度、波长等参量的变化量实现对磁场的测量的一类传感器。实现全光纤磁场传感器的原理有多种,例如法拉第效应、磁致伸缩效应、洛伦兹力和磁流体材料等等,其中法拉第效应由于可以实现对磁场的直接测量而广受欢迎。近年来,如何发展能够具有高灵敏度、高探测精度、大动态范围特点的新型光纤磁场传感器件成为了光纤传感领域的研究热点。本文主要内容如下:1.DBR(分布式布拉格反射)正交双频光纤激光器的研制。采用相位掩膜法,利用193nm Ar F准分子激光器在单掺铒光纤上刻写与模板波长对应的光纤光栅,制备出输出正交双偏振的单纵模DBR光纤光栅激光器。DBR光纤光栅激光器为光纤磁场传感器提供射频域的检测信号。2.利用法拉第效应,正交双偏振光纤激光器已被证明可用来实现灵活小巧的磁场传感器。为了发展适宜的封装结构以优化对磁场的传感灵敏度,提出了基于法拉第效应的正交双频光纤激光磁场传感器的纵向空间响应的测量。此外对传感器的磁场传感机理进行了分析,推导出在磁场中纵向空间响应与DBR光纤光栅激光器的关系。3.进行了磁场传感增强增敏性研究。通过旋转熔接法的增敏结构用以实验,这种方法可以引发快慢轴方向上相位差的减小,使得偏振态的光程差相互部分抵消,进而使输出拍频信号的频率得到降低。结合之前的实验及理论推导,可以使得光纤激光器的传感灵敏度得到进一步的提高。最后,对论文所做的内容作了简要的总结,对基于法拉第效应的光纤磁场传感器的进一步发展与应用作了展望。
[Abstract]:Magnetic field measurement has been widely used in many fields, such as navigation, current detection, space and geophysical research, etc. All optical fiber magnetic sensor is light because of its light weight. Optical fiber magnetic sensor is based on the optical fiber device as the sensitive element, through the help of phase, polarization state, amplitude. All optical fiber magnetic sensors have many principles, such as Faraday effect, magnetostrictive effect, Lorentz force and magnetic fluid materials. Faraday effect is popular because of its direct measurement of magnetic field. In recent years, how to develop high sensitivity and high detection accuracy. A novel optical fiber magnetic sensing device with large dynamic range has become a hotspot in the field of optical fiber sensing. The main contents of this paper are as follows: 1. DBR (distributed Bragg reflection). Development of orthogonal Dual-Frequency Fiber Laser. Phase mask method is used. A 193nm ar F excimer laser is used to write a fiber grating corresponding to the template wavelength on a single erbium-doped fiber. Single longitudinal mode DBR fiber grating laser with output orthogonal double polarization. DBR fiber grating laser provides RF detection signal for fiber magnetic sensor. 2. Using Faraday effect. Orthogonal double-polarization fiber lasers have been proved to be used to realize flexible and compact magnetic field sensors. In order to develop a suitable packaging structure to optimize the sensitivity to the magnetic field. The longitudinal spatial response of orthogonal dual-frequency fiber laser magnetic field sensor based on Faraday effect is proposed. In addition, the magnetic field sensing mechanism of the sensor is analyzed. The relationship between longitudinal spatial response in magnetic field and DBR fiber grating laser is deduced. The enhancement of sensitivity by magnetic field sensing is studied. This method can cause the decrease of phase difference in the direction of fast axis and slow axis, make the optical path difference of polarization state cancel each other, and then reduce the frequency of the output beat frequency signal. Combined with the previous experiments and theoretical derivation. The sensor sensitivity of fiber laser can be further improved. Finally, the content of this paper is summarized briefly. The further development and application of fiber optic magnetic field sensor based on Faraday effect are prospected.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP212;TN248

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