Research On High-efficiency Four-wave Mixing Based On Electromagnetic Induction And Transparent Phase Control

The atomic coherence and quantum interference cause many interesting and novel physical phenomena by the laser.One of the most significant phenomena is electromagnetically induced transparency-the interaction between the field and the medium,which originates by the quantum destructive interference effect between two pathways induced by another light.The propagation of a weak probe field in this medium shows many novel features,such as the suppression of absorption,the enhancement of the Kerr-nonlinearity,and reduction of group velocity.Because of these features,in recent years,it has become a hot research topic in the quantum field.Electromagnetically induced transparency can be used to increase the system's nonlinear polarization,enhance the efficiency of multi-wave mixing,etc.Because of its potential applications,multi-wave mixing has been studied by many researchers from the theoretical and experimental in the past few decades.At present,by using electromagnetically induced transparency to achieve highly efficient four-wave mixing has become one of the important methods.In this paper,we use phase to control four-wave mixing in the six-level tripod type atomic system based on the electromagnetically induced transparency.The paper is mainly divided into the following sections:In the first part,we mainly introduce the history of the development of electromagnetically induced transparency and four-wave mixing,as well as the theoretical explanation of electromagnetically induced transparency and four-wave mixing.Some specific examples are used to illustrate the research of four-wave mixing based on electromagnetic induction transparency in recent decades.The interaction principles between the optical and media are introduced in the second part,such as the Hamiltonian of interaction between the atom and the light field,the interacting picture,slow-varying-envelope approximation,rotating-waving approximation,the probability amplitude method and density matrix method.The third part is divided into two subsections.In the first subsection,we expound the role of relative phase in nonlinear optics with concrete examples.In second section,inspired by the Li's six-level tripod-type atomic scheme,we add a microwave field in their system,and then the added microwave field and other two coupled fields and energy levels can form a ring structure.It is shown that the conversion efficiency of four-wave mixing can be improved by adjusting the relative phase of the ring structure and the intensity of the microwave field.In the fourth part,we give a short summary of this thesis,and look forward to the prospects of efficient four-wave mixing in the field of science.