基于法拉第效应的双偏振光纤激光磁场传感器的纵向空间响应

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，有必要研究双偏振光纤激光磁场传感器在磁场中的空间响应特性。对长度为21 mm的光纤激光器在磁场宽度为3 mm、5 mm、7 mm以及磁场强度为0.5 T、 0.75 T和1 T时的纵向空间响应进行了实验研究。研究表明，沿着双偏振光纤激光磁场传感器的纵向，其各个部分对磁场的空间响应是不均匀的。该空间响应的峰值出现在激光腔的中间并沿激光器纵向呈对称的高斯分布。这种空间响应的分布特性与光纤光栅的分布式布拉格反射有关。

Longitudinal Spatial Response to Magnetic Field for a Faraday-rotation based Dual-Polarization Fiber Laser sensor

Based on Faraday effect, miniature and agile magnetic field sensor has been demonstrated by using a dual-polarization fiber grating laser. To develop suitable package to optimize the sensitivity to magnetic field, it is desired to study the spatial response of a dual-polarization fiber grating laser to magnetic field. Experiment measurements for the longitudinal spatial response to magnetic field have been performed on a fiber grating laser with a length of 21 mm in magnetic fields of 0.5 T, 0.75 T and 1 T and field widths of 3 mm, 5 mm and 7 mm. It shows that the spatial response is not uniform along the longitudinal direction of the dual-polarization fiber grating laser. The spatial response peaks at the center of the laser cavity and shows as a symmetric Gaussian distribution along the longitudinal direction of the laser. Such distribution characteristic of the spatial response is related to the distributed Bragg reflecting.