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We theoretically investigate the propagation of few-cycle laser pulses in resonant two-level dense media with a sub- wavelength structure, which is described by the full Maxwell-Bloch equations without the frame of slowly varying envelope and rotating wave approximations. The input pulses can be shaped into shorter ones with a single or less than one optical cycle. The effect of the parameters of the subwavelength structure and laser pulses is studied. Our study shows that the media with a subwavelength structure can significantly shape the few-cycle pulses into a subcycle pulse, even for the case of chirp pulses as input fields. This suggests that such subwavelength structures have potential application in the shaping of few-cycle laser pulses. 相似文献
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Nonlinear cascade-configuration multi-wave mixing scheme based on electromagnetically induced transparency 下载免费PDF全文
A nonlinear optical cascade-configuration multi-wave mixing (CCMWM) scheme is presented and analysed for the generation of coherent light in a six-level atomic system in the context of electromagnetically induced transparency (EIT). A detailed semi-classical study of the propagation of the generated mixing and probe fields is demonstrated. We show by numerical simulations that EIT is capable of suppressing linear and nonlinear photon absorption. The analytical dependence of the generated mixing field on the probe field and the respective detuning is also predicted. Such a nonlinear optical process can be used for generating coherent short-wavelength radiation. 相似文献
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Generation of NIulticomponent NIotional Coherent and Squeezed Coherent States of N Trapped Ions by a Dispersive Interaction 下载免费PDF全文
Following the recent proposal by Solano E et al. [Phys. Rev. Left. 87 (2001) 060402] a procedure is proposed to generate arbitrary discrete multicomponent motional coherent and squeezed coherent states of N trapped ions by additionally using a dispersive bichromatic interaction in a long-living and fast way. In this procedure, two lasers in the Raman configuration are tuned quasiresonant and resonant with N two-level ions under different conditions, respectively. Furthermore, we show how the idea can be used for the generation of two-mode SU(2) Schrdinger cat states for the vibrational motion of a single ion trapped in a two-dimensional harmonic potential. 相似文献
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Using Schrodinger-Maxwell formalism, we propose and analyze a continuous-wave four-wave mixing (FWM) scheme for the generation of coherent light in a six-level atomic system based on electromag-netically dual induced transparency. We derive the corresponding explicit analytical expressions for the generated mixing field. We find that the scheme greatly enhances FWM production efficiency and is also capable of inhibiting and delaying the onset of the detrimental three-photon destructive interference by choosing the proper decay rate in the second electromagnetically induced transparency (EIT) process. In addition, such an optical process also provides possibilities for producing short-wave-length coherent radiation at low pump intensities. 相似文献
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We discuss and analyze the absorption properties of a weak probe field in a typical four-level atomic system in the presence of a spontaneously generated coherence (SGC) term. The influences of the SGC and a coherent pump field on the probe absorption-amplification are investigated. The results show that the absorption of such a weak probe field can be dramatically enhanced due to the SGC effect. At the same time, the probe-absorption profile exhibits a two-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 SGC effect. 相似文献
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Possible Realization of Cluster States and Quantum Information Transfer in Cavity QED via Raman Transition 下载免费PDF全文
We present a scheme to generate cluster states with many scheme, no transfer of quantum information between the atoms in cavity QED via Raman transition. In this atoms and cavities is required, the cavity fields are only virtually excited and thus the cavity decay is suppressed during the generation of cluster states. The atoms are always populated in the two ground states. Therefore, the scheme is insensitive to the atomic spontaneous emission and cavity decay. We also show how to transfer quantum information from one atom to another. 相似文献
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叙述了磷离子注入方法诱导具有不同发射波长的InGaAsP双量子阱结构的混合,并通过光致发光谱和断面透射电子显微术对量子阱混合的程度进行了研究。在特定条件下快速热退火处理后,光致发光谱显示,在离子注入剂量低于7×1011/cm2情况下,两个阱的谱峰能保持较好的分离,注入剂量从1011 /cm2增大到1012/cm2的过程中,两个阱的带隙蓝移值都似乎存在一个极大值,并且在同样的条件下,上阱(发射波长为1.52 μm)的带隙蓝移值较下阱(发射波长为1.59 μm)大些。当离子注入剂量达到1012/cm2时,上阱的谱峰近乎消失,双阱光致发光谱出现了一个谱峰。用断面透射电子显微术对原生长样品与带隙蓝移具有极大值的退火样品进行微结构比较,结果显示,对比原生长样品,退火样品的晶格原子基本得到修复,但阱与垒间的界面显得模糊,这说明离子注入导致两阱完全混合。 相似文献
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Efficient three-wave mixing in a three-level atomic medium with an assisting microwave driven field 下载免费PDF全文
The potential for nonlinear conversion between two laser
pulses in a three-level V-type medium with assistance of an auxiliary
microwave resonant radiation is studied. The results show that
microwave driven field can lead to the parametric generation of a new
laser pulse with high conversion efficiency when a weak pump
laser pulse is applied. 相似文献
10.
We have established the master equation for the micromaser with a Kerr medium,we have studied the photon statics of the micromaser with a Kerr medium field and analysed the influence of the Kerr effect on the photon statistics,The influence of the Kerr effect on the photon statistics is different in two regimes,In the thermal-atom regime,the Kerr effect produces quantum noise,and decreases the mean photon number.In the ultracold-atom regime,with the increase of the nonlinear parameter of the Kerr medium,the stability of the mean photon number and the normalized variance enhances the mean photon number,and the normalized variance exhibits collapse-revival phenomena periodically,their resonance peaks become lower,and the photon statistics of more and more regions are sub-Poissonian. 相似文献