中国物理B ›› 2004, Vol. 13 ›› Issue (10): 1711-1716.doi: 10.1088/1009-1963/13/10/024

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Effect of relaxation rate on population distribution, EIT and refraction in Λ and V systems

孙庆青, 古英, 龚旗煌   

  1. State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
  • 收稿日期:2004-02-25 修回日期:2004-03-29 出版日期:2004-10-20 发布日期:2005-06-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10334010, 10304001, 10328407, and 90101027). Also by the National Key Basic Research Special Foundation (Grant No TG1999075207) and by the Scientific Research Foundation for

Effect of relaxation rate on population distribution, EIT and refraction in $\varLambda$ and V systems

Sun Qing-Qing (孙庆青), Gu Ying (古英), Gong Qi-Huang (龚旗煌)   

  1. State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
  • Received:2004-02-25 Revised:2004-03-29 Online:2004-10-20 Published:2005-06-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10334010, 10304001, 10328407, and 90101027). Also by the National Key Basic Research Special Foundation (Grant No TG1999075207) and by the Scientific Research Foundation for

摘要: In the three-level Λ-type and V-type systems, we find that the same pump-effect parameter R\left(=\dfrac{2|V_{c}|^{2}γ}{(ω_{ac}-ω_{c})^{2}+γ^{2}}\right) determines the population distributions, while the probe field leads to population fluctuations near the absorption peaks. With the increasing of the relaxation rate γ, the population distributions are shifted and their fluctuation amplitudes decrease. At the same time the electromagnetically induced transparency window becomes a broadened absorption peak, and the dispersion at the zero probe detuning changes from positive to negative. Large population fluctuation and non-fluctuation observed in different systems are attributed to the different relaxation rates.

关键词: relaxation rate, population distribution, pump-effect parameter

Abstract: In the three-level Λ-type and V-type systems, we find that the same pump-effect parameter $R(=\frac{2|V_c|^2\gamma}{(\omega_{ac}-\omega_c)^2+\gamma^2})$ determines the population distributions, while the probe field leads to population fluctuations near the absorption peaks. With the increasing of the relaxation rate $\gamma$, the population distributions are shifted and their fluctuation amplitudes decrease. At the same time the electromagnetically induced transparency window becomes a broadened absorption peak, and the dispersion at the zero probe detuning changes from positive to negative. Large population fluctuation and non-fluctuation observed in different systems are attributed to the different relaxation rates.

Key words: relaxation rate, population distribution, pump-effect parameter

中图分类号:  (Effects of atomic coherence on propagation, absorption, and Amplification of light; electromagnetically induced transparency and Absorption)

  • 42.50.Gy
32.80.Xx (Level crossing and optical pumping)