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

Acta Physica Sinica

The comparison of steady-state gain of V-type and Λ-type atomic systems of lasing without inversion

Chang Zeng-Guang, Jiancheng Liu, Yan Ke-zhu, (1)德州学院物理系,德州 253022; (2)曲阜师范大学物理工程学院,曲阜 273165

Published Jan 1, 2008• 4 citations
Publisher

Abstract

In this paper we study the dependence of steady-state gain of a closed V-type atomic system and a closed Λ-type atomic system of lasing without inversion on the detuning of the coherence lasers under the condition that the corresponding parameters of the two atomic systems are equal. By the way of numerical simulation and comparison, we find that the curves of probe-laser gain of the two atomic systems versus the detuning of probe-laser have similar shapes but their values are different, which are related to the characteristics of atomic coherence and population distribution of the two atomic systems directly. In addition, we find that the driving laser deturning and the additional atomic coherence caused by spontaneously generated coherence can exert a great influence upon the probe-laser gain.

DOI
10.7498/aps.57.4927

Related papers

Influence of Doppler broadening and spontaneously generated coherence on propagation effect in a quasi lambda-type four-level system

Zhongbo Liu, Ying Liang, Kening Jia +1 more

In this paper we study influences of Doppler broadening, spontaneously generated coherence, and other system parameters on propagation effect in a quasi lambda-type four-level atomic system. It is shown that when the Doppler broadening is present, generally speaking, the values of gain and intensity of lasing without inversion (i.e. the probe field) in the co-propagating probe and driving fields case are much larger than those in the counter-propagating case; considerably larger gain and intensity of lasing without inversion than those without the Doppler broadening can be obtained by choosing appropriate values of the Doppler broadening width and spontaneously generated coherence strength. The gain and intensity of lasing without inversion increase with the increase of spontaneously generated coherence strength; when spontaneously generated coherence is present, much larger gain and intensity of lasing without inversion than those in the case without spontaneously generated coherence can be obtained. Choosing suitable values of the probe detuning, Rabi frequencies of the driving and pump fields at the entrance of the medium also can remarkably enhance the gain and intensity of lasing without inversion.

Chinese Physics B•Feb 1, 2012•5 citations

Spontaneously Generated Coherence in an Open Four-level Atomic System

Fan Xi-jun

We put forward a model of an open quasi Λ-type four-level atomic system,and then investigate the effect of spontaneously generated coherence(SGC) on the gain of lasing without inversion from different respects by using the numerical calculation results of the system in the steady state.The study results show that,the switching from absorption to lasing without inversion(LWI) and the enhancement of the LWI gain can be realized by adjusting the strength of SGC;the variety of the two factors p1 to p2 which represent the SGC effect will produce remarkable different influence on the LWI gain.We also find that,the LWI gain is much larger in open system than that in the corresponding closed system;moreover,when the incoherent pump field is absent,the LWI gain can be obtained in the open system but cant in the closed system.

Journal of Optoelectronics·laser•Jan 1, 2007•0 citations

Influence of Doppler broadening and spontaneously generated coherence on propagation effect in a quasi lambda-type four-level system

刘中波, 梁颖, 贾克宁 +1 more

In this paper we study influences of Doppler broadening,spontaneously generated coherence,and other system parameters on propagation effect in a quasi lambda-type four-level atomic system.It is shown that when the Doppler broadening is present,generally speaking,the values of gain and intensity of lasing without inversion (i.e.the probe field) in the co-propagating probe and driving fields case are much larger than those in the counter-propagating case;considerably larger gain and intensity of lasing without inversion than those without the Doppler broadening can be obtained by choosing appropriate values of the Doppler broadening width and spontaneously generated coherence strength.The gain and intensity of lasing without inversion increase with the increase of spontaneously generated coherence strength;when spontaneously generated coherence is present,much larger gain and intensity of lasing without inversion than those in the case without spontaneously generated coherence can be obtained.Choosing suitable values of the probe detuning,Rabi frequencies of the driving and pump fields at the entrance of the medium also can remarkably enhance the gain and intensity of lasing without inversion.更多还原

Chinese Physics B•Jan 1, 2012•0 citations

Lasing without inversion in a closed four-level system

Cai, Li-Feng

We show lasing without population inversion in a closed four-level atomic system which is no longer incoherently pumped on the transition at which lasing occurs. The four-level system can overcome some limits in the typical lambda-type and V-type three-level systems, furthermore it is possible to achieve lasing even in the absence of the inversion condition for the thermal radiation fields or of the inversion of spontaneous decay rate. We find that when the detuning of probe field is equal to that of coherent coupling field, there is a peak value along with the increase of the detuning. To explain it, we bring forward that there are adiabatic and nonadiabatic stimulated Raman processes when a three-level atomic system is interacted with two coherent fields, so there are two mechanisms influencing the change of probe field. We believe that it can explain more general lasing without inversion processes because of quantum interference induced by coherent fields.

arXiv:quant-ph/0512009•Dec 1, 2005•1 citation

Phase control of light amplification without inversion in two Lambda-type atomic systems

Hai-Hua Wang, Jin‐Hui Wu, Jin-Yue Gao

We examine the gain property of a probe field interacting with two different three-level Lambda-type atomic systems with an open loop or a close loop. In the atomic system with an open loop, there exists quantum interference resulting from spontaneous emissions to two near-degenerate lower levels from a common upper level, and the weak probe field can be greatly amplified due to the spontaneously generated coherence. Moreover, the probe gain becomes sensitive to the relative phase between the probe and coupling fields, so we can realize phase control of the probe gain in principle. In the atomic system with a close loop, we use a microwave field to couple the two well-spaced lower levels so that quantum coherence similar to SGC can be generated. In this atomic system, we also can achieve the phase-sensitive probe gain due to the quantum interference between two different absorption channels for the probe field. Note, only in the case of three-photon resonance, this close-loop atomic system can reach a steady state. While in the case of three-photon off-resonance, the probe gain without inversion always oscillates periodically versus time, thus no steady-state probe gain can be achieved.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jan 11, 2005•0 citations

Effect of spontaneously generated coherence on inversionless lasing gain in an atomic system with Doppler broadening

Hui Ma, Xia Tan, Shufen Tian +2 more

We have studied the effect of the spontaneously generated coherence (SGC) on gain of lasing without inversion (LWI) in a closed three-level Λ-type atomic system with Doppler broadening. It is shown that, regardless of the driving and probe fields being co- or counter-propagating, at a suitable value of the Doppler width, we can obtain a much larger LWI gain with SGC than that without SGC; and the region of the LWI gain spectrum with SGC is obviously larger than that without SGC. When the Doppler width takes a constant value, the gain does not monotonically decrease or increase with increasing strength of SGC, the largest LWI gain can be obtained by adjusting strength of SGC. Generally speaking, the co-propagating probe and driving fields is favourable to obtain a larger LWI gain.

Chinese Physics•Aug 1, 2007•4 citations
In this paper we study the dependence of steady-state gain of a closed V-type atomic system and a closed Λ-type atomic system of lasing without inversion on the detuning of the coherence lasers under the condition that the corresponding parameters of the two atomic systems are equal. By the way of numerical simulation and comparison, we find that the curves of probe-laser gain of the two atomic systems versus the detuning of probe-laser have similar shapes but their values are different, which are related to the characteristics of atomic coherence and population distribution of the two atomic systems directly. In addition, we find that the driving laser deturning and the additional atomic coherence caused by spontaneously generated coherence can exert a great influence upon the probe-laser gain.
In this paper we study influences of Doppler broadening, spontaneously generated coherence, and other system parameters on propagation effect in a quasi lambda-type four-level atomic system. It is shown that when the Doppler broadening is present, generally speaking, the values of gain and intensity of lasing without inversion (i.e. the probe field) in the co-propagating probe and driving fields case are much larger than those in the counter-propagating case; considerably larger gain and intensity of lasing without inversion than those without the Doppler broadening can be obtained by choosing appropriate values of the Doppler broadening width and spontaneously generated coherence strength. The gain and intensity of lasing without inversion increase with the increase of spontaneously generated coherence strength; when spontaneously generated coherence is present, much larger gain and intensity of lasing without inversion than those in the case without spontaneously generated coherence can be obtained. Choosing suitable values of the probe detuning, Rabi frequencies of the driving and pump fields at the entrance of the medium also can remarkably enhance the gain and intensity of lasing without inversion.
We put forward a model of an open quasi Λ-type four-level atomic system,and then investigate the effect of spontaneously generated coherence(SGC) on the gain of lasing without inversion from different respects by using the numerical calculation results of the system in the steady state.The study results show that,the switching from absorption to lasing without inversion(LWI) and the enhancement of the LWI gain can be realized by adjusting the strength of SGC;the variety of the two factors p1 to p2 which represent the SGC effect will produce remarkable different influence on the LWI gain.We also find that,the LWI gain is much larger in open system than that in the corresponding closed system;moreover,when the incoherent pump field is absent,the LWI gain can be obtained in the open system but cant in the closed system.
In this paper we study influences of Doppler broadening,spontaneously generated coherence,and other system parameters on propagation effect in a quasi lambda-type four-level atomic system.It is shown that when the Doppler broadening is present,generally speaking,the values of gain and intensity of lasing without inversion (i.e.the probe field) in the co-propagating probe and driving fields case are much larger than those in the counter-propagating case;considerably larger gain and intensity of lasing without inversion than those without the Doppler broadening can be obtained by choosing appropriate values of the Doppler broadening width and spontaneously generated coherence strength.The gain and intensity of lasing without inversion increase with the increase of spontaneously generated coherence strength;when spontaneously generated coherence is present,much larger gain and intensity of lasing without inversion than those in the case without spontaneously generated coherence can be obtained.Choosing suitable values of the probe detuning,Rabi frequencies of the driving and pump fields at the entrance of the medium also can remarkably enhance the gain and intensity of lasing without inversion.更多还原
We show lasing without population inversion in a closed four-level atomic system which is no longer incoherently pumped on the transition at which lasing occurs. The four-level system can overcome some limits in the typical lambda-type and V-type three-level systems, furthermore it is possible to achieve lasing even in the absence of the inversion condition for the thermal radiation fields or of the inversion of spontaneous decay rate. We find that when the detuning of probe field is equal to that of coherent coupling field, there is a peak value along with the increase of the detuning. To explain it, we bring forward that there are adiabatic and nonadiabatic stimulated Raman processes when a three-level atomic system is interacted with two coherent fields, so there are two mechanisms influencing the change of probe field. We believe that it can explain more general lasing without inversion processes because of quantum interference induced by coherent fields.
We examine the gain property of a probe field interacting with two different three-level Lambda-type atomic systems with an open loop or a close loop. In the atomic system with an open loop, there exists quantum interference resulting from spontaneous emissions to two near-degenerate lower levels from a common upper level, and the weak probe field can be greatly amplified due to the spontaneously generated coherence. Moreover, the probe gain becomes sensitive to the relative phase between the probe and coupling fields, so we can realize phase control of the probe gain in principle. In the atomic system with a close loop, we use a microwave field to couple the two well-spaced lower levels so that quantum coherence similar to SGC can be generated. In this atomic system, we also can achieve the phase-sensitive probe gain due to the quantum interference between two different absorption channels for the probe field. Note, only in the case of three-photon resonance, this close-loop atomic system can reach a steady state. While in the case of three-photon off-resonance, the probe gain without inversion always oscillates periodically versus time, thus no steady-state probe gain can be achieved.
We have studied the effect of the spontaneously generated coherence (SGC) on gain of lasing without inversion (LWI) in a closed three-level Λ-type atomic system with Doppler broadening. It is shown that, regardless of the driving and probe fields being co- or counter-propagating, at a suitable value of the Doppler width, we can obtain a much larger LWI gain with SGC than that without SGC; and the region of the LWI gain spectrum with SGC is obviously larger than that without SGC. When the Doppler width takes a constant value, the gain does not monotonically decrease or increase with increasing strength of SGC, the largest LWI gain can be obtained by adjusting strength of SGC. Generally speaking, the co-propagating probe and driving fields is favourable to obtain a larger LWI gain.