Creation of isotropic super-resolved magnetization with steerable orientation

Weichao Yan,Yuxiao Wang,Yinglin Song,Xiaofei Liu,Zhongquan Nie,Xueru Zhang

doi:10.1063/1.5042571

Abstract

In this work, we present a feasible pathway for initially constructing light-induced isotropic super-resolved magnetization along with steerable orientations and trivial side-lobe levels. Toward this end, the counter-propagating azimuthally polarized vortex Hermite–Gauss beams are tailored with angular rotators at the exit pupil planes and then focused by using high numerical aperture objective lenses in a 4π optical microscopic configuration. By wilfully regulating the rotatable azimuth angle and judiciously optimizing the scaling parameter, the spherical super-resolved (λ3/24), orientation-tunable (any direction), and sidelobe-negligible (&lt;20%) magnetization spot can thus be produced. Such well-defined magnetization behavior is attributed to not merely the axially symmetrical destruction of the incoming vectorial fields but also the constructive interference in all directions caused by all the magnetization components. The demonstrated outcomes hold great potential in developing novel magneto-optical and spin-photonic devices.

Highlights

The interaction between light beams and magnetic materials has aroused intensive research interest due to the vast prospectives in all-optical magnetic recording (AOMR),[1,2,3] confocal and magnetic resonance microscopy,[4,5] atom trapping,[6,7] magnetic encryption,[8,9,10] and multi-value high density magneto-optical (MO) storage composed of multiple state values.[11,12,13]
In spite of the tremendous prospects, there are threefold problems that have hitherto remained challenging in the opto-magnetization realm. (i) The shape of the magnetization pattern should be a spherical spot with three-dimensional (3D) super-resolution volume beyond the diffraction limit (
(ii) To avoid data cross talk in AOMR, the sidelobe value of the magnetization spot should be propelled to a negligible level (

Summary

Introduction

The interaction between light beams and magnetic materials has aroused intensive research interest due to the vast prospectives in all-optical magnetic recording (AOMR),[1,2,3] confocal and magnetic resonance microscopy,[4,5] atom trapping,[6,7] magnetic encryption,[8,9,10] and multi-value high density magneto-optical (MO) storage composed of multiple state values.[11,12,13] In spite of the tremendous prospects, there are threefold problems that have hitherto remained challenging in the opto-magnetization realm. (i) The shape of the magnetization pattern should be a spherical spot with three-dimensional (3D) super-resolution volume beyond the diffraction limit (

Results

Conclusion