In this Letter, all-optical generation of magnetization with arbitrary three-dimensional (3D) orientations is numerically demonstrated through the inverse Faraday effect (IFE) by using a reversing calculation method. The IFE-induced magnetization with an expected 3D orientation is initially conceived by coherently configuring two orthogonally arranged electric dipoles with a phase difference of $\pi /2$ in the focal region of a to-be-determined incident light field. Based on the dipole antenna theory, this required incident light field can be deduced analytically according to the orientations of the electric dipoles. By utilizing this field as illumination and reversing the field propagation, magnetization with the expected orientation can be obtained in the focal region through the IFE. Moreover, this method showcases a high magnetization orientation purity (greater than 93%) within the focal volume defined by the full width at half maximum when the numerical aperture of the focal lens is 0.95. This result demonstrates extended flexibility of magnetization manipulations in an all-optical fashion and possesses great potential in spintronics and all-optical magnetic recording.

中文翻译：

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具有任意三维方向的磁化全光生成

在这封信中，通过使用反向计算方法，通过反法拉第效应（IFE）在数值上演示了具有任意三维（3D）取向的全光磁化产生。首先，通过相干配置两个相位差为0的正交排列的电偶极子，初步构想出具有预期3D方向的IFE感应磁化。$\pi /\mathrm{2个}$在待确定的入射光场的焦点区域中。基于偶极子天线理论，可以根据电偶极子的方向解析地推导出所需的入射光场。通过将该场用作照明并反转场传播，可以通过IFE在焦点区域中获得具有预期方向的磁化强度。而且，当聚焦透镜的数值孔径为0.95时，该方法在由半峰全宽限定的聚焦体积内显示出高的磁化取向纯度（大于93％）。该结果证明了全光方式的磁化操作的扩展灵活性，并且在自旋电子学和全光磁记录中具有巨大的潜力。