Huge enhancement of magneto-optical Faraday effect by localization of light and its applications

(1)光局域化对磁光Faraday和Kerr效应的增强理论计算表明，与光局域化相关的磁光效应的增强是由于右旋和左旋圆偏振光的局域化波长略有不同造成的，这两种光是磁化平行于光传播方向的磁性薄膜中的光的本征模式。计算结果也可以从理论上解释，其结果与数值结果完全一致。在此基础上，研究了支持强局域光的多层膜。研究发现，具有微腔结构的薄膜能够很好地支持光的局域化，从而表现出相当大的磁光效应。光在多层膜中的局域效应与一维光子晶体中的局域模和…密切相关(2)Co、非晶态TbFe或稀土铁石榴石薄膜磁光微腔的制备及其性能在上述结果的基础上，制备了(SiO_2/SiN)k/Co/(SiN/SiO_2)^k，(SiO_2/SiN)^k，(SiO_2/SiO_2)^k/a-TbFe/(SiN/SiO_2)^k，采用射频溅射方法制备了(SiO_2/Ta_2O_5)、k/Bi：DyIG/(Ta2O5/SiO_2)结构，并对其光学和磁光性能进行了研究。这些薄膜的光学和磁光性质在定量上与上述理论结果很好地吻合。特别是，支持强局域光的薄膜表现出很大的磁光Faraday或Kerr效应，其旋转角大约是传统磁性单层薄膜的100倍。这些结果表明，利用光的局域化可以有效地实现各种磁光器件。(3)磁光子晶体本研究中所研究的多层膜可以看作是具有自旋相关光学性质的一维光子晶体(磁光晶体)。从这一点出发，研究了上述薄膜与一维介电光子晶体的关系。结果表明，在具有有序和/或无序结构的磁光晶体中，利用光的局域化可以增强磁光效应。从这些结果来看，二维和三维磁光晶体变得非常有吸引力，尽管其基本性质尚不清楚。因此，有必要对高维磁光晶体进行进一步的研究。较少

(1) Enhancement of magneto-optical Faraday and Kerr effects due to localization of lightTheoretical calculations revealed that the enhancement of magneto-optical effect associated with the localization of light is caused by the slight difference in localization wavelengths of fight-hand and left-hand circular polarized lights that are eigenmodes of lights in a magnetic film with magnetization parallel to the propagation direction of light. The computational results can be also explained from the theory, whose results coincide with the numerical results completely.Based on these results, multilayer films that support the strong localization of light were investigated. It was found that the films with microcavity structures can support the strong localization of light and, as a result, the films exhibit considerably large magneto-optical effects. The localization effect of light in the multilayer films closely relates to the localized mode in the one-dimensional photonic crystals, and th … More e mechanism of the localization effect and the resultant magneto-optical effect of the one-dimensional photonic crystals composed of magnetic materials (magnetophotonic crystals) were discussed in detail.(2) Fabrication of magneto-optical microcavities with Co, amorphous TbFe, or rare-earth iron garnet films, and their propertiesBased on the above results, films with (SiO_2/SiN)k/Co/(SiN/SiO_2)^k, (SiO_2/SiN)^k/a-TbFe/(SiN/SiO_2)^k, (SiO_2/Ta_2O_5)^k/Bi : DyIG/(Ta2O5/SiO2) structures were fabricated by means of RF sputtering and their optical and magneto-optical properties were investigated. These films showed optical and magneto-optical properties that coincide the above theoretical results quantitatively very well. In particular, the films supporting the strong localization of light showed large magneto-optical Faraday or Kerr effects, whose rotation angles are approximately 100 times larger than those of conventional magnetic single-layer films. These results indicate that the use of the localization of light is effective for realizing various magneto-optical devices.(3) Magnetophotonic crystalsThe multilayer films investigated in this study can be regarded as one-dimensional photonic crystals with spin-dependent optical properties (magnetophotonic cyrstals). From this respect, relation between the above films and the one-dimensional dielectric photonic crystals was studied. As a result, it is concluded that, in the magnetophotonic crystals with ordered and/or disordered structures, magneto-optical effect can be enhanced by the use of localization of light, From these results, two- and three-dimensional magnetophotonic crystals become very attractive, though their fundamental properties are still unclear. Then, further studies on magnetophotonic crystals with higher dimensions are necessary. Less