提出了一种基于光纤三维微结构加工的磁场传感技术方案。利用波长为780nm的飞秒激光脉冲在刻写有光纤布拉格光栅(FBG)的单模光纤包层上加工螺旋微结构,并采用磁控溅射方法在其上溅射磁致伸缩膜(TbDyFe),制备了一种新型光纤磁场传感器探头。微结构能改善光纤轴向伸缩性,增加薄膜沉积的表面积,从而提高探头的磁场敏感性。建立了螺旋微结构改善传感灵敏度的理论基础,介绍了光纤磁场传感探头的制备工艺方法与技巧,给出了不同参数传感探头的磁场测试结果。实验结果表明,螺距为50μm时,对应的传感探头对磁场最为敏感;相比于无微结构的标准光纤探头,有微结构的光纤探头理想情况下灵敏度可提高近5倍。 A scheme of magnetic field sensing based on three-dimensional optical microstructure processing is proposed. Spiral microstructures were fabricated on a single-mode fiber cladding engraved with a fiber Bragg grating (FBG) using a femtosecond laser pulse at a wavelength of 780 nm and a magnetostrictive film (TbDyFe) was sputtered thereon using a magnetron sputtering method. A novel optical fiber magnetic field sensor probe was fabricated. Microstructure can improve the optical fiber axial flexibility, increase the surface area of ​​the film deposition, thereby enhancing the magnetic field sensitivity of the probe. The theoretical basis for improving the sensing sensitivity of the spiral microstructure is established. The preparation methods and techniques of the fiber magnetic field sensing probe are introduced. The magnetic field test results of different parameters of the sensing probe are given. The experimental results show that the corresponding sensing probe is the most sensitive to the magnetic field when the pitch is 50μm. Compared with the standard fiber probe without microstructure, the fiber probe with microstructure can improve the sensitivity by nearly 5 times under ideal conditions.