Study On Vortex Four-Wave-Mixing In Multi-level Atomic System

Over the past decades,the four-wave mixing in the ultraslow propagation regime has been widely studied in atomic vapors.For instance,electromagnetic induced transparency,multi-photon quantum coherence and dual electromagnetic induced transparency have been proposed to realize the high-efficiency four-wave mixing.However,the above studies do not consider the spatial characteristics of orbital angular momentum of light.As a hot topic in recent years,vortex light carrying orbital angular momentum has many applications in quantum information and quantum optics because of its abundant properties in the interaction between light and matter.In this paper,based on orbital angular momentum light,we study the vortex four-wave mixing in an ultraslow propagation regime.As a result,the method and theoretical analyses that are proposed here will be helpful for the study of orbital angular momentum light in quantum optics and quantum information science.Orbital angular momentum light is nowadays an intriguing resource in classical and quantum optics due to the richness of physical properties it shows in interaction with matter.First,we study the ultra-slow vortex four-wave mixing in four-level atomic systems by multi-photon quantum interference.We find that the structured information of orbital angular momentum light can be manipulated via two-photon detuning and three photon detuning.At the same time,we also give a detailed explanation based on the dispersion relation,and the results are in good agreement with our simulation results.Moreover,to describe the spatial modulation more clearly,we interfere the four-wave mixing field with the same-frequency Gaussian beam.The results show that the interference mode can also be controlled by multi-photon detunings.Our work may have potential applications in quantum manipulation based on orbital angular momentum light.Then,we propose a scheme for modulating the vortex four-wave mixing in a five-level atomic system.During nonlinear four-wave mixing process,we find the vortex four-wave mixing field can be easily manipulated by adjusting the corresponding parameters.Practically,the orbital angular momentum phase can be spatially modulated and the detailed explanations based on the dispersion relation are given.Furthermore,we show the superposition modes of the four-wave mixing field and a same-frequency Gaussian beam,and the superposition patterns can also be controlled via the corresponding parameters.Our results may be helpful to study nonlinear quantum phenomena based on orbital angular momentum light.