一维磁流体掺杂光子晶体缺陷模的磁控可调特性

磁流体的有效介电常数 与磁性粒子体积分数P和外加磁场因子 有关。本文首先计算了水基MnFe2O4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 的变化关系，发现通过调节外加磁场因子 的大小可实现不同纳米磁性粒子体积分数P的磁流体具有相同的有效折射率。然后，应用传输矩阵法，数值模拟了水基MnFe2O4磁流体中的纳米磁性粒子体积分数P=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：缺陷模随着磁流体有效折射率nc的增大出现红移现象，即缺陷模中心波长随着随有效折射率nc的增大而变长，最大改变量为36.6nm。最后讨论了缺陷模品质因子 ，发现缺陷模半峰值带宽 不变，缺陷模品质因子 与缺陷模波长 随磁流体有效折射率nc的变化具有相同的线性变化特性，即品质因子 随有效折射率nc的增大而增大。

Characteristics of magnetic-controlled tuning in doping one-dimensional magnetic fluid photonic crystal defect mode

The effective dielectric constant of magnetic fluid is related to the volume fraction P of the magnetic nanoparticles and the factor of magnetic field. Firstly, in this paper, the changing relation of water-based MnFe2O4 nanoparticle magnetic fluid effective refractive index as the changing of which are the volume fraction of the magnetic nanoparticles and the factor of magnetic field is caculated. It is found that though the factor of magnetic field is adjusted. To realize the magnetic fluid has the same effective refractive index in difference of volume fraction of the magnetic nanoparticles. And then, the transmission spectrum of doping one-dimensional water-based MnFe2O4 magnetic fluid photonic crystal, the volume fraction of the magnetic nanoparticles 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 the increased of nanoparticle magnetic fluid effective refractive index. That is, the wavelength of defect modes increased as the effective refractive index of magnetic fluid increasing. The amount of redshift is 36.6nm. At last, the quality factor of defect mode is disscused. We found out that half the peak bandwidth is a constant. The quality factor of defect mode and the wavelength of defect mode have the same characteristics of linear with the change of the effective refractive index of magnetic fluid. That is, the quality factor of the defect mode increased as the effective refractive index of magnetic fluid increasing.