磁流体的折射率可调谐特性分析

从理论上分析出温度和磁场是影响磁流体折射率的两大因素，并根据菲涅尔反射原理设计具有独立传感探头的磁流体折射率特性测量方案，实验得出温度和磁场对磁流体折射率的影响特性.结果表明:对于浓度一定的磁流体，在零磁场作用下，折射率随着温度的升高线性下降，灵敏度为-802×10-5℃-1;温度恒定时，在外加平行磁场作用下，磁流体的折射率随着磁场强度的增大而增大，且结果具有良好的一致性.得到的磁流体的可调谐折射率特性为磁流体填充到光子晶体光纤(光栅)中实现磁场和温度传感提供了理论基础.

Analysis of Tunable Refractive Index Characteristics of the Magnetic Fluid

Temperature and magnetic field are the two factors which will affect the magnetic fluid refractive index through theoretical analysis. A method with independent sensing probes based on the principle of Fresnel reflection was presented. Experimental measurements were carried out to investigate the relation between the magnetic field intensity and temperature dependent refractive index of the magnetic fluid. The results showed that， for a given concentration of the magnetic fluid， the effect of temperature on nMF was relatively insignificant with a sensitivity of -802×10-5℃-1 under zero magnetic field intensity. When there was an external magnetic field(parallel to the propagation direction of light)， the nMF would increase with the increase of the magnetic field intensity at constant temperature. The repeatable performance of this device was also proved to be perfect. The tunable refractive index characteristics of magnetic fluid could be used as the theoretical basement for filling into the photonic crystal fiber(grating)to achieve a magnetic field and temperature sensing.