Theoretical Study On The Interaction Of Atomic And Tightly Focused Hybrid-order Poincaré Sphere Beams

Ultra-cold atomic gases have important applications in quantum simulation,precision measurement,and quantum information.Among these researchs,lasers are important tools for manipulating quantum dynamics of the atomic gases.Various spatial structures and polarizations of the lasers are important resources.The recently developed hybrid-order Poincaré lights have either the characteristics of vortex light and a rich polarization structure.Potentially providing new means to manipulating cold atoms.For this purpose,we have studied the interaction of tightly focused hybrid-order Poincaré light and atoms.In this thesis,we first study the spin density of the tightly focused hybrid-order Poincaré beams(TFPB),we find that has a longitudinal component and a transvers components.Unlike tightly focused full Poincaré beams whose longitudinal spin density is zero on average,the total longitudinal spin of the TFPB is not zero.The spin density of TFPB has rich controllable spatial pattern,especially,the longitudinal spin density can have ring shape,or regular polygon shape.These features can be used to separate chiral particles,or to manipulate dynamics of ultracold spinot gases.We further apply the theory of interaction between the atoms an arbitrarily polarized light field far away from resonance to study the Stark interaction potential of the atoms by the tightly focused Poincaré beams.We numerically investigate the motion of the atom in the light field,and discussed the influence of the initial condition of the atom on the motion trajectory,which will have potential for the trapping and guiding of cold atoms,molecules and microscopic particles.