Effect Of The Counter-Rotating Component On Theoptical Properties Of An InAs/GaAs Quantum Dot Structure

Supported by the National High Technology Research and Development Program of China (Grant No.2009AA03Z405), the National Natural Science Foundation of China (Grant No.60908028), this dissertation analyzes theoretically the phenomenon of electromagnetically induced transparency (EIT) in atomic systems and quantum-dot system, and numerically investigates EIT in the quantum dot structure. We study the effect of the counter-rotating component to the EIT. The main contents are as follows:First, based on the basic theory of the interaction of the light and atoms, we have studied the dark state. Using the density matrix under the application in the interaction picture in the rotating wave approximation and dipole approximation, we theoretically study the electromagnetically induced transparency effect inΔ-type three-level atom system, and discuss the frequency dispersion and absorption properties in the system in the weak probe field. In the cascade-type InAs/GaAs quantum dot model, by using the rotating wave approximation, we discuss the effect of EIT in the quantum dot system. It can reduce the group velocity of light in media by the use of EIT effect as slow light. For researching the effect of counter-rotating component to the EIT in the cascade-type InAs/GaAs quantum dots model in the strong pump field, we respectively investigate the frequency dispersion and absorption characters when the combined effect of the rotating component and the counter-rotating component work on the two-level and three-level systems. We find that the absorption peak of the system is the symmetric bimodal in the RWA. The absorption spectra of systems accrues frequency offset by considering the effect of counter-rotating approximation, and with the Rabi oscillation frequency of the pump field increases, the offset increases, and the absorption peak is asymmetric. In contrast, we study the three-level atom system coupling to the two mostly resonance field by considering the counter-rotating component. It proves that the effect of the counter-rotating component cannot be ignored in quantum dot system in the strong field. The result has guiding significance to the theoretical and experimental research in the future. Finally, to compare the effect of the A-T and the EIT phenomenon, we study the four kinds of three-level atom system model, respectively such asΔ-type, cascade-EIT type, V-type and cascade-AT type model by introducing the threshold factor. According to the different values of the threshold factor, there comes a new classification in different strength coupling system. Although the A-T splitting and the electromagnetically induced transparency are similarities in the absorption spectrum, but are different in nature. Through the discussion of the results, we further clarify the physical explanation to the electromagnetically induced transparency phenomenon.