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Phase control in an open A-type system with spontaneously generated coherence 被引量:4
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作者 崔妮 樊锡君 +3 位作者 李爱云 刘呈普 龚尚庆 徐至展 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第3期718-724,共7页
This paper investigates the control role of the relative phase between the probe and driving fields on the gain, dispersion and populations in an open A system with spontaneously generated coherence (SGC). It shows ... This paper investigates the control role of the relative phase between the probe and driving fields on the gain, dispersion and populations in an open A system with spontaneously generated coherence (SGC). It shows that by adjusting the value of the relative phase, a change from lasing with inversion to lasing without inversion can be realized; the values and frequency spectrum regions of the inversionless gain and dispersion can be obviously varied; high refractive index with zero absorption and electromagnetically induced transparency can be achieved. It is also found that when the driving field is resonant, the shapes of the dispersion and the gain curves versus the probe detuning are very similar if the relative phase of the dispersion lags π/2 than that of the gain, however for the off-resonant driving field the similarity will disappear; the gain, dispersion and populations are periodical functions of the relative phase, the modulation period is always 2π; the contribution of SGC to the inversionless gain and dispersion is much larger than that of the dynamically induced coherence. 展开更多
关键词 spontaneously generated coherence phase control electromagnetically induced transparency lasing without inversion
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Effect of spontaneously generated coherence on inversionless lasing gain in an atomic system with Doppler broadening 被引量:3
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作者 马慧 谭霞 +2 位作者 田淑芬 仝殿民 樊锡君 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第8期2400-2406,共7页
We have studied the effect of the spontaneously generated coherence (SGC) on gain of lasing without inversion (LWI) in a closed three-level A-type atomic system with Doppler broadening. It is shown that, regardles... We have studied the effect of the spontaneously generated coherence (SGC) on gain of lasing without inversion (LWI) in a closed three-level A-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. 展开更多
关键词 spontaneously generated coherence Doppler broadening lasing without inversion GAIN
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Influence of Doppler broadening and spontaneously generated coherence on propagation effect in a quasi lambda-type four-level system 被引量:1
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作者 Liu Zhong-Bo Liang Ying +1 位作者 Jia Ke-Ning Fan Xi-Jun 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第2期322-332,共11页
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 ... 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. 展开更多
关键词 four-level system propagation effect spontaneously generated coherence Doppler broadening lasing without inversion
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Phase control of light amplification in steady and transient processes in an inverted-Y atomic system with spontaneously generated coherence
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作者 田思聪 佟存柱 +7 位作者 万仁刚 宁永强 秦丽 刘云 王立军 张航 王增斌 高锦岳 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第4期279-287,共9页
We investigate the effects of spontaneously generated coherence (SGC) on both the steady and transient gain properties in a four-level inverted-Y-type atomic system in the presence of a weak probe, two strong cohere... We investigate the effects of spontaneously generated coherence (SGC) on both the steady and transient gain properties in a four-level inverted-Y-type atomic system in the presence of a weak probe, two strong coherent fields, and an incoherent pump. For the steady process, we find that the inversionless gain mainly origins from SGC. In particular, we can modulate the inversionless gain by changing the relative phase between the two fields. Moreover, the amplitude of the gain peak can be enhanced and the additional gain peak can appear by changing the detuning of the coupling field. As for the transient process, the transient gain properties can also be dramatically affected by the SGC. Compared to the case without SGC, the transient gain can be greatly enhanced with completely eliminated transient absorption by choosing the proper relative phase between the two fields. And the inverted-Y-type system with SGC can be simulated in both atomic and semiconductor quantum well systems avoiding the conditions of SGC. 展开更多
关键词 spontaneously generated coherence gain without inversion transient evolution relative phase
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Observation of linewidth narrowing due to a spontaneously generated coherence effect
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作者 田思聪 王春亮 +7 位作者 康智慧 杨秀彬 万仁刚 张晓军 张航 姜云 崔海宁 高锦岳 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期216-222,共7页
We investigate the resonance fluorescence spectrum of an atomic three-level ladder system driven by two laser fields. We show that such a system emulates to a large degree a V-type atom with parallel dipole moments-th... We investigate the resonance fluorescence spectrum of an atomic three-level ladder system driven by two laser fields. We show that such a system emulates to a large degree a V-type atom with parallel dipole moments-the latter being a system that exhibits spontaneously generated coherence and can display ultrasharp spectral lines. We find a suitable energy scheme in a SSRb atom and experimentally observe the narrowing of the central peak in a rubidium atomic beam. The corresponding spectrum can convindngiy demonstrate the existence of spontaneously generated coherence. 展开更多
关键词 spontaneously generated coherence resonance fluorescence linewidth narrowing atomicbeam
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Effects of Spontaneously Generated Coherence on Intensity-Intensity Correlation in a Driven Y-Type Atom
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作者 王飞 石文星 龚成 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第12期1079-1083,共5页
In this paper,we investigate the spontaneously generated coherence(SGC) effects on the fluorescence fields intensity-intensity correlation in a resonant driven four-level Y-type atomic system.By using a strong control... In this paper,we investigate the spontaneously generated coherence(SGC) effects on the fluorescence fields intensity-intensity correlation in a resonant driven four-level Y-type atomic system.By using a strong control field, in the absense of SGC effects,strong correlation and anticorrelation fluorescence photons can be produced from two ladder transitions in this system respectively.However,in the presence of SGC effects,the fluorescence fields correlation properties are reversed for the two transitions.The above phenomena can be traced to the quantum destructive or constructive interference in terms of dressed states. 展开更多
关键词 intensity-intensity correlation spontaneously generated coherence
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Probe gain via four-wave mixing based on spontaneously generated coherence
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作者 Hong Yang Ting-gui Zhang Yan Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第2期223-228,共6页
We have studied the probe gain via a double-Λ atomic system with a pair of closely lying lower levels in the presence of two probe and two coherent pump fields. The inversionless gain can be realized by using nondege... We have studied the probe gain via a double-Λ atomic system with a pair of closely lying lower levels in the presence of two probe and two coherent pump fields. The inversionless gain can be realized by using nondegenerate four-wave mixing under the condition of spontaneously generated coherence(SGC) owing to near-degenerate lower levels. Note that by using SGC, two probe fields can be amplified with more remarkable amplitudes, and the gain spectra of an extremely narrow linewidth can be obtained. Last but not least, our results show that the probe gain is quite sensitive to relative phases due to the SGC presence which allows one to modulate the gain spectra periodically by phase modulation, and can also be influenced by all laser field intensities and frequencies, and the angles between dipole elements. 展开更多
关键词 probe gain four-wave mixing spontaneously generated coherence narrow spectra linewidth
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Storage and Retrieval of a Weak Optical Signal Improved by Spontaneously Generated Coherence in an Atomic Assemble
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作者 郑涛 邱田会 杨国建 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第3期463-467,共5页
We investigate the reversible storage of a weak single-mode light signal in a A-type three-level atomic system with spontaneously generated coherence (SGC) and pumped by an incoherent field. The scheme is phase-depe... We investigate the reversible storage of a weak single-mode light signal in a A-type three-level atomic system with spontaneously generated coherence (SGC) and pumped by an incoherent field. The scheme is phase-dependent. If the phase of the controlling field is set oppositely to that of the signal field, the combination of SGC with weak pump overcomes the drawback of incompletely retrieval in the conventional scheme, leading to 100% retrieval fidelity or even to the amplification of the retrieved signal with respect to its initial one. 展开更多
关键词 reversible storage electromagnetically induced transparency spontaneously generated coherence
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the phase-dependent gain without inversion in a Doppler broadened open four-level system
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作者 刘中波 贾克宁 +2 位作者 梁颖 仝殿民 樊锡君 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期227-233,共7页
It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase ... It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase between the probe field and the driving field; the atomic exit rate (R0) and the ratio (S) of the atomic injection rates have a considerable modulation effect on the phase-dependent GWI. GWI first increases and then decreases with R0 increasing; in a certain value range of S, GWI increases monotonically with S increasing; by adjusting the values of R0 and S, in an open system a much larger GWI can be obtained than in the corresponding closed system [2011 Phys. Rev. A 83 043805]. The modulation effects of R0 and S on the phase-dependent GWI in the case with the counter-propagating probe and driving fields are stronger than those in the co-propagating case, GWI in the co-propagating case is much larger than that in the counter-propagating case. 展开更多
关键词 open N-type four-level system spontaneously generated coherence relative phase Doppler broadening gain without inversion
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SGC Switching Between Subluminal to Superluminal Propagation in V-Type Atom
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作者 HAN Ding-An GUO Hong +2 位作者 BAI Yan-Feng SUN Hui ZENG Ya-Guang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第4X期731-734,共4页
For a V-type three-level atomic system with two closely spaced upper levels, we investigate the light pulse propagation properties with only one laser field. Due to spontaneously generated coherence, the group velocit... For a V-type three-level atomic system with two closely spaced upper levels, we investigate the light pulse propagation properties with only one laser field. Due to spontaneously generated coherence, the group velocity of the light pulse can be changed from subluminal to superluminal. The effects of the field intensity and the two-upper level splitting on the group velocity are also shown. At last, an analytical expression for the group velocity is given in the case of a weak field. 展开更多
关键词 spontaneously generated coherence SUPERLUMINAL SUBLUMINAL
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Three-Level Λ-Type Atomic System Localized by the Parameters of the Two Orthogonal Standing-Wave Fields
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作者 Shuncai Zhao Qixuan Wu 《Journal of Applied Mathematics and Physics》 2016年第8期1546-1553,共8页
Localization of the three-level Λ-type atomic system interacting with two orthogonal standing-wave fields is proposed. Two equal and tunable peaks in the 2D plane are obtained by the detunings corresponding to the tw... Localization of the three-level Λ-type atomic system interacting with two orthogonal standing-wave fields is proposed. Two equal and tunable peaks in the 2D plane are obtained by the detunings corresponding to the two orthogonal standing-wave fields when the decreasing intensities of spontaneously generated coherence (SGC) arise in the three-level Λ-type atomic system, while one circular ring with shrinking radii in the 2D plane is obtained by the adjusted phases and wave vectors of the standing-wave fields when the increasing intensities of SGC occur in the three-level Λ-type atomic system. 2D atom localization with the single ring with shrinking radii realized by the multiple parametric manipulations demonstrated the flexibility for our scheme. 展开更多
关键词 Three-Level Λ-Type Atomic System Atom Localization spontaneously generated coherence (SGC)
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Modulation of atomic exit and injection rates on the phase-dependent gain without inversion in a Doppler broadened open four-level system
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作者 刘中波 贾克宁 +2 位作者 梁颖 仝殿民 樊锡君 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期231-237,共1页
It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase betw... It is shown that in a Doppler broadened open N-type four-level atomic system with spontaneously generated coherence (SGC), the gain without inversion (GWI) is very sensitive to the variation of the relative phase between the probe field and the driving field; the atomic exit rate (R0) and the ratio (S) of the atomic injection rates have a considerable modulation effect on the phase-dependent GWI. GWI first increases and then decreases with R0 increasing; in a certain value range of S, GWI increases monotonically with S increasing; by adjusting the values of R0 and S, in an open system a much larger GWI can be obtained than in the corresponding closed system [2011 Phys. Rev. A 83 043805]. The modulation effects of R0 and S on the phase-dependent GWI in the case with the counter-propagating probe and driving fields are stronger than those in the co-propagating case, GWI in the co-propagating case is much larger than that in the counter-propagating case. 展开更多
关键词 open N-type four-level system spontaneously generated coherence relative phase Doppler broadening gain without inversion
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Impact of Interacting Quantum Coherence via Decays and Incoherent Pumping on Transient and Steady-State Behaviors of Absorption
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作者 白艳锋 刘太刚 +1 位作者 喻小强 杨文星 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第4期677-680,共4页
The effects from quantum coherence via decays and incoherent pumping on the lasing without inversion(LWI) are investigated in a four-level system.By analyzing the transient and steady-state behaviors of the absorption... The effects from quantum coherence via decays and incoherent pumping on the lasing without inversion(LWI) are investigated in a four-level system.By analyzing the transient and steady-state behaviors of the absorption,we find that the gain occurs when both spontaneously generated coherence(SGC) and coherence induced by incoherent pumping(IPC) are considered.We attribute the occurrence of the gain to the interaction of quantum coherence via decays and incoherent pumping. 展开更多
关键词 gain without inversion spontaneously generated coherence coherence induced by incoherent pumping
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Phase-Controlled Transparent Superluminal Light Propagation in a Doppler-Broadened Four-Level N-Type System 被引量:1
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作者 Lida Ebrahimi Zohravi Majid Abedi Mohammad Mahmoudi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2014年第4期506-516,共11页
The propagation of a weak probe field in a four-level N-type quantum system in the presence of spontaneously generated coherence(SGC) is theoretically investigated. The optical properties of the system are studied and... The propagation of a weak probe field in a four-level N-type quantum system in the presence of spontaneously generated coherence(SGC) is theoretically investigated. The optical properties of the system are studied and it is shown that the group velocity of light pulse can be controlled by relative phase of applied fields. By changing the relative phase of applied fields, the group velocity of light pulse changes from transparent subluminal to the transparent superluminal light propagation. Thus, the phase-controlled absorption-free superluminal light propagation is obtained without applying an incoherent laser fields to the system. The propagation of a weak probe light pulse is studied by solving the Maxwell's wave equation on numerical grid in space and time. Moreover, we study the third order self- and cross-Kerr susceptibility of probe field and calculate the nonlinear cross-phase shift for different values of intensity of applied fields. In addition, we take into account the effect of Doppler broadening on the light pulse propagation and it is found that a suitable choice of laser propagation directions allows us to preserve our results even in the presence of Doppler effect. It is demonstrated that by increasing the Doppler width of distribution to the room temperature,the dispersion changes from transparent subluminal to transparent superluminal light propagation which is our major motivation for this work. 展开更多
关键词 coherent control spontaneously generated coherence SUPERLUMINAL
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