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

(1)光局域化引起的磁光法拉第效应和克尔效应的增强理论计算表明，光局域化引起的磁光效应的增强是由于在磁化方向平行于光传播方向的磁性薄膜中，光的本征模--左旋圆偏振光和右旋圆偏振光的局域波长略有不同所致。计算结果也可以从理论上得到解释，其结果与数值计算结果完全吻合。在此基础上，研究了支持强光局域化的多层膜。结果表明，具有微腔结构的薄膜可以支持强的光局域化，从而表现出相当大的磁光效应。光在多层膜中的局域化效应与一维光子晶体中的局域模密切相关， 关于我们 详细讨论了由磁性材料构成的一维光子晶体（磁光子晶体）的局域化效应和由此产生的磁光效应的机理。(2)Co、非晶TbFe、稀土铁石榴石薄膜磁光微腔的制备及其性能研究（SiO_2/SiN）k/Co/（SiN/SiO_2）^k，（SiO_2/SiN）^k/a-TbFe/（SiN/SiO_2）^k，采用射频溅射法制备了（SiO_2/Ta_2O_5）^k/Bi：DyIG/（Ta_2O_5/SiO_2）结构，并对其光学和磁光特性进行了研究。这些薄膜的光学和磁光性质与上述理论结果定量吻合。特别地，支持光的强局域化的膜显示出大的磁光法拉第或克尔效应，其旋转角比常规磁性单层膜的旋转角大大约100倍。这些结果表明，利用光的局域化是实现各种磁光器件的有效方法。(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（磁光子晶体）。从这方面研究了上述薄膜与一维介质光子晶体的关系。结果表明，在具有有序和无序结构的磁光子晶体中，利用光的局域化可以增强磁光效应。从这些结果可以看出，二维和三维磁光子晶体是非常有吸引力的，尽管它们的基本性质还不清楚。因此，需要对更高维度的磁光子晶体进行进一步的研究。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