Research On The Optical Bistable Characteristics Of Three-level Atoms Inside An Optical Cavity

Pure optical bistability (OB) has wide rang of applications such as all opticalswitch, light storage, optical transistors and light amplification. It has advantages offast switching speed, immunity to electromagnetic interference.And optical bistabilitywill get pratical application on the optical communication and optical informationprocessing. Therefor it has attracted a lot of attention in recent year. At present, atomicelectromagnetically induced transparency(EIT) effect improves the research oftraditional pure OB and optical multistability(OM) properties very deeply. It showsthat the OB and OM can be controlled in various atomic optical bistable system.Thismakes the application of pure optical bistable system in all-optical communicationand optical quantum information processing possible.In this thesis, we mainly study the optical bistable system of a three-level Λ-typeatomic system in unidirectional ring cavity. The OB, OM, dynamic instability andchaos have studied at length in the two case of long and short delay. In the long timedelay conditions, we have theoretically studied the intensity and the frequencydetuning of the coupling field on the influence of medium properties when couplingfield interact with three-level Λ-type atomic system. On this basis, we achieve theeffective adjustment of the optical bistable threshold. At the same time, the influenceof the coherent relaxation rate of two low level dipolar forbidden transition on atomicOB behavior is also discussed. We find that the change of the relaxation rate on thebistability threshold is very obvious in a certain range, but the coherent therelaxation rate is determined by the characteristics of the medium. Therefor, weintroduced microwave driving field and analyzed of the intensity of the microwavefield on the bistability in detail, and we found that when the intensity of themicrowave field is not strong enough, the OB or OM can be realized by adjusting theintensity of the coupling field and frequency detuning. In the short time delayconditions, We analyze the influence of the Kerr nonlinearity effect to the index ofrefraction.We take frequency detuning of the coupling field as the bifurcationparameter when we study the dynamics behavior of the system by the power spectra and timing diagram of system output.We found that when the frequency detuning ofthe coupling field decreases gradually,the oscillation pattern keeps the same but theoscillation period and oscillation amplitude change continuously.The results of the study, partly promote the development of OB system and itmakes pure optical bistable system to provide the necessary theoretical basis forapplication in optical computing and quantum information processing.