Yi Yuxuan, Yang Hua, Sun Tangyou, Yi Zao, Zhou Zigang, Liu Chao, Yi Yougen
School of Mathematics and Science, Joint Laboratory for Extreme Conditions Matter Properties, The State Key Laboratory of Environment-Friendly Energy Materials, Tianfu Institute of Research and Innovation, Southwest University of Science and Technology, Mianyang 621010, China.
School of Science, Lanzhou University of Technology, Lanzhou 730050, China.
Sensors (Basel). 2025 Jun 24;25(13):3931. doi: 10.3390/s25133931.
To enhance the sensing performance of fiber-optic magnetic field sensors, we explored the design, optimization, and application prospects of a D-type fiber-optic magnetic field sensor. This D-type PCF-SPR sensor is metal coated on one side (the metal used in this study is gold), which serves as the active metal for SPR and enhances structural stability. Magnetic fluid is applied on the outer side of the gold film for SPR magnetic field sensing. Six internal air holes arranged in a hexagonal shape form a central light transmission channel that facilitates the connection between the two modes, which are the sensor's core mode and SPP mode, respectively. The outer six large air holes and two small air holes are arranged in a circular pattern to form the cladding, which allows for better energy transmission and reduces energy loss in the fiber. In this paper, the finite element method is employed to analyze the transmission performance of the sensor, focusing on the transmission mode. Guidelines for optimizing the PCF-SPR sensor are derived from analyzing the fiber optic sensor's dispersion curve, the impact of surface plasmon excitation mode, and the core mode energy on sensing performance. After analyzing and optimizing the transmission mode and structural parameters, the optimized sensor achieves a magnetic field sensitivity of 18,500 pm/mT and a resolution of 54 nT. This performance is several orders of magnitude higher than most other sensors in terms of sensitivity and resolution. The SPR-PCF magnetic field sensor offers highly sensitive and accurate magnetic field measurements and shows promising applications in medical and industrial fields.
为提高光纤磁场传感器的传感性能，我们探索了一种D型光纤磁场传感器的设计、优化及应用前景。这种D型光子晶体光纤表面等离子体共振（PCF-SPR）传感器一侧涂覆有金属（本研究中使用的金属是金），该金属作为表面等离子体共振的活性金属，并增强了结构稳定性。在金膜外侧施加磁流体用于表面等离子体共振磁场传感。六个呈六边形排列的内部空气孔形成一个中心光传输通道，便于分别作为传感器的核心模式和表面等离子体激元（SPP）模式的两种模式之间的连接。外部的六个大气孔和两个小气孔呈圆形排列以形成包层，这有利于更好的能量传输并减少光纤中的能量损失。本文采用有限元方法分析传感器的传输性能，重点关注传输模式。通过分析光纤传感器的色散曲线、表面等离子体激元激发模式的影响以及核心模式能量对传感性能的影响，得出了优化光子晶体光纤表面等离子体共振传感器的指导原则。在对传输模式和结构参数进行分析和优化后，优化后的传感器实现了18500 pm/mT的磁场灵敏度和54 nT的分辨率。就灵敏度和分辨率而言，该性能比大多数其他传感器高出几个数量级。表面等离子体共振 - 光子晶体光纤磁场传感器提供了高灵敏度和高精度的磁场测量，并在医疗和工业领域显示出广阔的应用前景。
