Pulse Propagation Properties In The Quasi-Λ-type Four-level Atomic Medium

Quantum coherence effects can completely change the optical properties of the medium, resulting in a lot of interesting phenomena in fundamental physics research and practical applications.First, this paper has theoretically studied the propagations of Gaussian and Oπ probe pulses in the strong-field-driven quasi-A-type four-level atomic medium system. The results show that with the same medium conditions and the same pulse width of frequency, the Gaussian probe light splitted by the middle absorption peak to a low-frequency packet and a high-frequency packet,the two packets interference causes the output spectrum wave changed significantly;Detection characteristics of the Oπ light spectrum, the Oπ probe beam doesn’t split leading to its ideal transparency.Second, we have theoretically studied the propagation of Gaussian probe pulse in the strong-field-driven cascade-type three-level atomic medium system. The results show that when the pump light resonance with the atoms and the pump intensity is small and the width of the electromagnetically induced transparency window narrower than the width of the optical,the output spectrum of Gaussian broadening,the intensity weakened.Large detuning causes down of one of the two absorption peaks,low absorption peak of the probe beam absorption effects were significantly weaker than the other absorption peak weak resulting in clear differences between the output spectrum.