Research On Light-induced Magnetization Field Regulation Based On IFE Theory

In recent years,the development of ultrashort laser pulse technology has provided an effective tool for studying the interaction of light with matter on extreme time scales.The inverse Faraday effect induced magnetization field caused by laser action on magnetic materials has a wide range of applications in all-optical magnetic recording,big data storage,particle trapping and co-aggregation microscopy.In order to break the magnetic recording limitation of the traditional two-dimensional space,the magnetization orientation,which is one of the characteristics of the magnetization field,gradually becomes the key to the regulation of the magnetization field.The magnetization field orientation control is further combined with the magnetization field intensity control,enabling more new effects and new applications to be realized.Firstly,this paper introduces the tight focus theory and the inverse Faraday effect,numerically simulates the intensity distribution of magnetization induced by circularly polarized beams and vector polarized beams,and experimentally detects the magnetization field distribution of the first-order azimuthally polarized vortex beams.The existence of the helicity-dependent magnetization reversal was confirmed.Secondly,a method based on dipole radiation theory to construct a three-dimensional arbitrary orientation magnetization field is proposed.The magnetization orientation of the light-induced magnetization field at a single focus can be dynamically regulated by loading the calculated pupil field.The method is performed under a single lens system and is simple and flexible to operate.Finally,based on the single focus orientation design,the needle magnetization field is obtained by using the antenna array far field radiation theory calculation.The magnetization orientation of the magnetization needle can be controlled by controlling the field entering the pupil plane.With the introduction of a multi-focus design,a multi-layer oriented controllable magnetization needle array can be obtained.The application of magnetization field in magnetic information multiplexing can be extended by orientation coding.