带缺陷结构的二维磁性光子晶体的数值模拟分析

Numerical analysis of two-dimensional magnetophotonic crystals with structural defects

利用频域有限差分方法分析了多种带缺陷结构二维磁性光子晶体(二重对称,四重对称和六重对称结构)的法拉第旋转角与椭圆率的变化特性.结果表明:在这些结构中,光波均被局域在中心缺陷处;同时,对于具有四重对称轴结构的材料,在其法拉第旋转角增加的同时,出射光波的椭圆率没有明显的增加;但对于不具有四重对称轴结构的材料,其法拉第旋转角增加的同时,出射光波的椭圆率也在增加.因此,只有在具有四重对称轴结构的二维磁性光子晶体中引入缺陷,才能很好地抑制光波偏振态的变化.这种带缺陷的二维磁性光子晶体结构有可能用于制作磁性光子晶体光纤.

The Faraday rotation of two-dimensional magnetophotonic crystals （including those with fourfold-symmetry and non-fourfold- symmetry） with structural defects and the ellipticity of outgoing optical waves are analyzed by using finite-difference frequency- domain （FDFD） method. The numerical simulation results show that the localization of the light wave in the vicinity of central defect occurs in these types of the structure. With increasing Faraday rotation of fourfold-symmetry structures, the change of the ellipticity of outgoing optical waves from these structures is unobvious. In contrast, the increases of the ellipticity of outgoing optical waves are obvious with the raise of Faraday rotation in non-fourfold-symmetry structures. It is concluded that introducing defects to the fourfold-symmetry structure constrains the change of the state of polarization of optical waves. This kind of twodimensional magnetophotonic crystal with structural defects may be used to manufacture magnetophotonic crystal fiber.