Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Communications in Theoretical Physics

Large Enhancement of Probe Amplification with Population Inversion in a Four-Level Atomic System with Vacuum-Induced Coherence

Jiahua Li, Wen‐Xing Yang, Luo Jin-Ming, Peng Ju-Cun

Published May 1, 2005• 3 citations
Publisher

Abstract

In this paper, we discuss and analyze theoretically probe absorption-amplification response in a four-level coherent atomic system with vacuum-induced coherence via changing the sign of the parameter f , with f denoting the ratio of a pair of dipole moments associated with a doublet of closely upper hyperfine sublevels. We find that the amplitude of the probe amplification for the case f = −1 can be about one order of magnitude larger than that achievable for the case f = 1. In addition, with respect to the case f = −1 the probe amplification can be maintained all the time with weak incoherent pumping for a wide range of the probe detuning.

DOI
10.1088/0253-6102/43/5/029

Related papers

Probe gain with population inversion in a four-level atomic system with vacuum-induced coherence

Jin‐Hui Wu, Huifang Zhang, Jin-Yue Gao

For a four-level atomic system with a doublet of closely spaced levels, we find that, owing to the coherence that results from the vacuum of the radiation field, population trapping at excited levels and probe gain with population inversion can be achieved with weak incoherent pumping. This gain is different from both the conventional lasing gain and gain without inversion in that there exists population inversion on probe transitions but the inversion is achieved by the vacuum-induced coherence.

Optics Letters•Apr 15, 2003•34 citations

Absorption-Dispersion Properties in a Four-Level Atomic System with Vacuum-Induced Coherence

Hua Wei, Jiahua Li, Zhiming Zhan +1 more

We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (EIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.

Communications in Theoretical Physics•Jul 1, 2005•1 citation

Absorption-Amplification Response with or Without Spontaneously Generated Coherence in a Coherent Four-Level Atomic Medium

Jiahua Li, Wen‐Xing Yang, Peng Ju-Cun

We discuss and analyze the absorption-amplification properties of a weak probe field in a typical four-level atomic system in the presence of an additional coherence term, the spontaneously generated coherence term. The influences of the spontaneously generated coherence and a coherent pump field on the probe absorption (amplification) are investigated in detail. We show that the absorption of such a weak probe field can be dramatically enhanced due to the presence of the spontaneously generated coherence. At the same time, the probe-absorption profile exhibits the double-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On the contrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved by adjusting the coherent pump field intensity in the absence of the spontaneously generated coherence.

Communications in Theoretical Physics•Sep 15, 2004•7 citations

Vacuum induced interference effect in probe absorption in a driven Y-type atom

Bibhas Kumar Dutta, P.K. Mahapatra

We have analyzed the properties of weak probe absorption in a closed four-level Y -type system driven by a coherent driving field. The system with two nearly degenerate uppermost levels interacting with the same modes of the vacuum radiation field exhibits the interference effect between the spontaneous decay channels. The phenomenon of this quantum interference can significantly change the absorptive response of the weak probe field. On varying the amplitude of the resonant driving field, in the absence of incoherent pumping in the upper transitions the system can display probe transparency as well as enhanced absorption peak under the condition of resonant detuning of the probe field. With the application of incoherent pumping to the system the phenomenon of symmetric light amplification with two distinct gain peaks one each at the positions of Autler–Townes resonances can be achieved in the presence of the decay-interference effect. We have also shown that the unidirectional incoherent pumping mode is necessary for the evolution of probe gain.

Journal of Physics B Atomic Molecular and Optical Physics•Feb 26, 2008•22 citations

Absorption-Dispersion Properties in a Four-Level Atomic System with Vacuum-Induced Coherence

Weihua, LIJia-Hua, ZHANZhi-Ming +1 more

We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (EIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.

理论物理通讯：英文版•Jan 1, 2005•0 citations

Absorption-Dispersion Properties in a Four-Level Atomic System with Vacuum-Induced Coherence

Wei Wei, Hua, Li +5 more

We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (EIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.

理论物理通讯：英文版•Jan 1, 2005•0 citations
In this paper, we discuss and analyze theoretically probe absorption-amplification response in a four-level coherent atomic system with vacuum-induced coherence via changing the sign of the parameter f , with f denoting the ratio of a pair of dipole moments associated with a doublet of closely upper hyperfine sublevels. We find that the amplitude of the probe amplification for the case f = −1 can be about one order of magnitude larger than that achievable for the case f = 1. In addition, with respect to the case f = −1 the probe amplification can be maintained all the time with weak incoherent pumping for a wide range of the probe detuning.
For a four-level atomic system with a doublet of closely spaced levels, we find that, owing to the coherence that results from the vacuum of the radiation field, population trapping at excited levels and probe gain with population inversion can be achieved with weak incoherent pumping. This gain is different from both the conventional lasing gain and gain without inversion in that there exists population inversion on probe transitions but the inversion is achieved by the vacuum-induced coherence.
We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (EIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.
We discuss and analyze the absorption-amplification properties of a weak probe field in a typical four-level atomic system in the presence of an additional coherence term, the spontaneously generated coherence term. The influences of the spontaneously generated coherence and a coherent pump field on the probe absorption (amplification) are investigated in detail. We show that the absorption of such a weak probe field can be dramatically enhanced due to the presence of the spontaneously generated coherence. At the same time, the probe-absorption profile exhibits the double-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On the contrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved by adjusting the coherent pump field intensity in the absence of the spontaneously generated coherence.
We have analyzed the properties of weak probe absorption in a closed four-level Y -type system driven by a coherent driving field. The system with two nearly degenerate uppermost levels interacting with the same modes of the vacuum radiation field exhibits the interference effect between the spontaneous decay channels. The phenomenon of this quantum interference can significantly change the absorptive response of the weak probe field. On varying the amplitude of the resonant driving field, in the absence of incoherent pumping in the upper transitions the system can display probe transparency as well as enhanced absorption peak under the condition of resonant detuning of the probe field. With the application of incoherent pumping to the system the phenomenon of symmetric light amplification with two distinct gain peaks one each at the positions of Autler–Townes resonances can be achieved in the presence of the decay-interference effect. We have also shown that the unidirectional incoherent pumping mode is necessary for the evolution of probe gain.
We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (EIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.
We discuss and analyze absorption-dispersion response for the probe field in a typical four-level atomic system with vacuum-induced coherence (VIC) arising from the cross coupling pathways associated with a pair of upper excited hyperfine levels. We find that VIC effect can preserve electromagnetically induced transparency (EIT) by using the detailed numerical simulations based on the density-matrix equations and analytical calculations in the dressed-state picture. We also show that the atomic hyperfine structure cannot be a hindrance to obtaining EIT.