磁流体的有效介电常数εliq 与磁性粒子体积分数P和外加磁场因子α∥ 有关。计算了水基MnFe2 O4 磁流体的有效折射率随纳米磁性粒子体积分数P和外加磁场强度因子α∥ 的变化关系,发现通过调节α∥ 的大小可实现不同纳米磁性粒子体积分数的磁流体具有相同的有效折射率。应用传输矩阵法, 数值模拟了水基MnFe2 O4 磁流体中P为0.745时结构为(AB)8C(BA)8的一维磁流体掺 杂光子晶体的透射谱。结果表明:缺陷模磁流体nc的增大出现红移现象,即缺陷模中心 波长随nc的增大而变长,最大改变量为36.6 nm。讨论了缺陷模品质因子Q, 发现缺陷模半峰值带宽不变,Q与缺陷模波长 随nc的变化具有相同的线性变化特性,即Q 随有效折射率的增大而增大。

The effective dielectric constant εliq of magnetic fluid is related to the volume fraction P of the magnetic nanoparticles and the factor α∥ of magnetic field. The changing relation of water-based MnFe2 O4 nanoparticle magnetic fluid effective refractive index with the volume fraction of the magnetic nanoparticles P and the factor of magnetic field α∥ was caculated. It was found that by adjusting α∥, the magnetic fluid has the same effective refractive index in difference of volume fraction of the magnetic nanoparticles. The transmission spectrum of doping one-dimensional water-based MnFe2 O4 magnetic fluid photonic crystal, when P is 0.745 and the structure is (AB)8C(BA)8, is numerically simulated by transfer matrix method. The results indicate that the wavelength of defect mode shifts to the side of long waves as increasing of nanoparticle magnetic fluid effective refractive index nc. That is, the wavelength of defect modes increase as increasing of nc. The amount of redshift is 36.6 nm. The quality factor of defect mode was disscused. It’s found that half of the peak bandwidth λw is a constant. The quality factor of defect mode Q and the wavelength of defect mode λ have the same characteristics of linear with the change of nc. That is, Q increases with the increasing of nc.