Research On Spin/Orbital Angular Momentum And Their Interaction Of Structured Light Fields In Chiral Media

In recent years,due to its unique physical properties,novel physical effects and potential applications,structured light fields has become a research hotspot in the field of Optics and optoelectronics.As a special form of electromagnetic wave,the interaction between structured light field and matter with specific amplitude,phase and polarization distribution is accompanied by the transfer of photon energy and photon momentum and angular momentum.At the same time,it presents a series of novel physical effects and phenomena,such as Rotating Doppler Effect,All-optical Switching Effect,Spin Hall Effect,transverse spin,spiral mutation,and chirality dependence and so on.On the other hand,chiral materials exist widely in nature,and the research of chiral materials is a basic and important topic.Chiral materials are widely used in life science,drug research and discovery,precision machining and metamaterials.In this paper,the structure light field with special amplitude,phase and polarization distribution is introduced into the study of chiral materials,and the spin/orbital angular momentum and their interaction of structure light fields in chiral media is analyzed.The main contents are as follows:1.Through the vector potential method and the vector angle spectrum expansion method and their combine,the expressions of electromagnetic field components of typical structure beams,such as Laguerre Gaussian beams,Bessel beams and Airy beams,are derived,and the detailed numerical simulation results are given,and the characteristics of the structured light fields are analyzed.2.Based on Collins formula and ABCD matrix of chiral medium,the propagation expressions of three typical structural light fields in chiral medium,namely Laguerre Gaussian beams,Bessel beams and Airy beams,are derived,and the propagation characteristics of the light fields are analyzed.The full vector theoretical analysis model of the reflection and refraction of the structural light fields at the interface of chiral medium is established,and different polarization states Laguerre Gaussian beams are derived as an example.The expression of the electromagnetic field components of the beam after reflection and refraction at the interface of the medium in the reduced state is analyzed.The influence of the incident angle on the field distribution of the reflected and refracted light is analyzed.3.According to the expression of electromagnetic components of structured light fields and the definition of GH and IF displacement,the equivalency of the two calculation methods from field expression and angular spectrum expression is verified.At the same time,the expressions of transverse and longitudinal spatial or angular shit of Laguerre Gaussian beams,Bessel beams and Airy beams are given,and the factors affecting the displacement are analyzed.The reflection and refraction at the interface of chiral medium are analyzed.The variation of spin and orbital angular momentum of Laguerre Gaussian beam with incident angle is analyzed.The influence of topological charge number and polarization state on spin and orbital angular momentum is studied.The interaction between spin and orbital angular momentum of structural light field in chiral medium is discussed.