Luo Jianjun, Zhang Henwen, Wang Sicong, Shi Liu, Zhu Zhuqing, Gu Bing, Wang Xiaolei, Li Xiangping
Opt Lett. 2019 Feb 15;44(4):727-730. doi: 10.1364/OL.44.000727.
Based on the Richards-Wolf vectorial diffraction theory and inverse Faraday effect, we first propose a scheme to generate three-dimensional magnetization needle (MN) arrays with arbitrary orientation for each individual needle and controllable spatial position and number by reversing the electric dipole array radiation. To achieve this, each unit of the electric dipole array has two electric dipoles with orthogonal oscillation directions and quadrature phase and is located mirror-symmetric with respect to the focal plane of the high numerical aperture lens. Uniformly distributed MNs with a subwavelength lateral size of 0.44λ and a longitudinal depth of 5.36λ with four different orientations are obtained by optimized arrangement for 2N (here, N=2) units of the electric dipole array. The corresponding purity of MNs is also discussed in detail. Furthermore, two combinations of MN arrays with orthogonal orientation are emphatically exploited in the hybrid bit-patterned media recording. The results illustrate the richness of the proposed methods to locally control the particular orientation properties of the MN and find many potential applications in multichannel/multilayer magneto-optical storage, information security, and spintronics.
基于理查兹-沃尔夫矢量衍射理论和逆法拉第效应，我们首次提出了一种方案，通过反转电偶极子阵列辐射来生成三维磁化针（MN）阵列，其中每个针的方向任意，空间位置和数量可控。为实现这一点，电偶极子阵列的每个单元有两个振荡方向正交且相位正交的电偶极子，并相对于高数值孔径透镜的焦平面镜像对称放置。通过对2N（这里N = 2）个电偶极子阵列单元进行优化排列，获得了横向尺寸为0.44λ、纵向深度为5.36λ且具有四种不同方向的均匀分布的MN，其横向尺寸小于波长。还详细讨论了相应的MN纯度。此外，在混合位图案介质记录中着重研究了具有正交方向的两种MN阵列组合。结果表明，所提出的方法在局部控制MN的特定取向特性方面具有丰富性，并在多通道/多层磁光存储、信息安全和自旋电子学等方面发现了许多潜在应用。
