The magnetic fluid sensor is proposed and numerically investigated by using finite-element-method (FEM) based on the photonic crystal fiber (PCF) with butterfly-shaped air holes and a ring core. Ethanol is used as a magnetic fluid that is injected in the ring core which provides unique characteristics. The goal of the proposed structure is to gain a better response to birefringence and relative sensitivity. In this work, the observed birefringence is \(1.27\times {10}^{-2}\); the sensitivity responses are 40 nm/Oe, and 94047.13 nm/RIU can be gained for the variations of magnetic field strength from 50 to 200 Oe and 200 Oe, respectively. With best of knowledge, this sensitivity response is the highest response in the magnetic sensing. For better sensing performance the proposed butterfly structure can be used in the bio-optics field and nanofluidic technologies.

提出并基于有限元法（FEM）对磁流体传感器进行了数值研究，该方法基于具有蝴蝶形气孔和环形芯的光子晶体光纤（PCF）。乙醇用作磁流体注入环形芯中，具有独特的特性。所提出的结构的目的是获得对双折射和相对灵敏度的更好的响应。在这项工作中，观察到的双折射为\（1.27 \ times {10} ^ {-2} \）; 磁场强度从50到200 Oe和200 Oe的变化，灵敏度响应分别为40 nm / Oe和94047.13 nm / RIU。以最先进的知识，这种灵敏度响应是磁传感中的最高响应。为了获得更好的感测性能，建议的蝶形结构可用于生物光学领域和纳米流体技术。