The Study On Airy-like Beam Of Magnetostatic Surface Spin Waves

With geometric approximation,light travels along a straight line in a uniform medium.However,if the electromagnetic wave nature of light is taken into account,diffraction will occur if an obstacle is encountered during propagation.In another case,the beam with finite width will be broadened during free propagation due to diffraction effect.Recently,non-diffracting beams have attracted much attention from researchers,such as Bessel beam,Mathieu beam and Airy beam.The Airy beam is a typical non-diffracting beam.In addition to its non-diffraction and self-healing properties,it also presents self-acceleration characteristics during propagation.Until now,Airy beams are applied to various forms of waves,such as surface plasmons,electron beams,sound waves,and water waves.Considering the extensive advances of spin wave in recent years,this paper introduces the Airy oscillation form into the spin wave field.And the micromagnetic simulation was performed to study the propagation dynamics of the Airy-like beam of magnetostatic surface spin waves(AiBMSSW)on the magnetic film.The research content and results are listed as follows:1.Based on the principle of 3/2 Phase-only pattern,AiBMSSW is achieved with micromagnetic simulation and its propagation dynamics properties are studied.The simulation results show that the AiBMSSW can be efficiently generated based on the3/2 Phase-only modulation,and the main lobe trajectory exhibits self-acceleration characteristics.In addition,the effects of antenna length L and the bias magnetic field magnetic induction B₀ on the trajectory of AiBMSSW are systematically studied.With fixed bias magnetic field,the larger the length L of the antenna,the larger the initial main lobe width of AiBMSSW,and the slower the self-acceleration;On the other hand,with fixed antenna length L,the self-acceleration of the AiBMSSW is sped up with increased bias magnetic field magnetic induction B₀.2.The non-diffraction and self-healing properties of AiBMSSW were studied.Through the comparison of the full width at half maximum(FWHM)of the main lobe,AiBMSSW has almost the same FWHM of the main lobe at a certain propagation distance.When the first main lobe is occluded at first,it can be retrieval after a certain propagation distance,and the distance between the occlusion area and the antenna does not change the trajectory of the reconstructed main lobe.3.Three experimental designs of the excitation antenna of AiBMSSW are proposed.A binarized phase thickness modulated antenna,a binarized phase width modulated antenna and a curved width modulated antenna.The propagation dynamics of AiBMSSW excited by three kinds of antennas are studied by micromagnetic simulation.The results show that the three antennas designed can effectively excite AiBMSSW in magnetic films.The AiBMSSW excitation antenna designed in this paper provides theoretical support and scheme design for the corresponding experimental research.