排序方式: 共有32条查询结果,搜索用时 15 毫秒
21.
从理论上讨论了囚禁于两电介质间的级联三能级系统薄原子蒸汽膜的色散特性.由于腔中慢速原子及泵浦-探测机制的速度选择贡献,色散谱线表现为Dicke窄化的亚多普勒结构及明显的慢光效应,当泵浦光和探测光异侧入射时这种现象更为突出.两个叠加的色散线型,一个对应光学泵浦,另一个对应可能出现的电磁诱致透明. 相似文献
22.
Fifth-order attosecond sum-frequency polarization beat (FASPB) is studied in a cascade three level system with the phase-conjugation fourth-order coherence function theory. An improved schematic diagram of geometry, which is different from that inducing fifth-order femtosecond different-frequency polarization beat (FFDPB), is used to obtain FASPB. By analyzing the cases that pump beams have either narrow or broad bandwidth, it is found that the temporal behavior of the sum-frequency polarization beat signal depends on the properties of the lasers and transverse relaxation rate of the atomic energy-level system. Finally, the cascaded four-wave mixing (FWM) processes and the difference between attosecond and femtosecond polarization beats have been discussed, it is found that cascaded or sequential lower processes can often obscure the direct fifth-order polarization beat processes. 相似文献
23.
研究了受强缀饰场作用的五能级原子系统所产生的多波混频共存特性.研究发现,通过调节激光束方向,沿同一方向出射的八波混频、双缀饰四波混频和单缀饰六波混频信号因共用能级的原子相干产生而出现竞争现象,通过控制缀饰场减弱四波混频和六波混频信号强度,可以达到增强八波混频信号的目的.还对级联和并联两种不同缀饰方式下双缀饰四波混频过程的差别进行了详细分析.
关键词:
双缀饰四波混频
单缀饰六波混频
八波混频
抑制增强 相似文献
24.
基于两双光子过程的相位共轭二阶极化干涉,从理论上研究了四能级系统在阿秒量级的不对称和频极化拍频(FASPB).在抽运光束为窄带情形下,场关联对FASPB信号影响很弱.在宽带情形下,FASPB信号表现出共振-非共振交叉关联,双光子信号展现出混合辐射-物质失谐的THz阻尼振荡,即当激光频率偏离双光子共振跃迁的条件时,信号将呈现阻尼振荡,而且其双光子自相关信号的包络还呈现最大值零延时不对称.还研究了由于两双光子自相关过程零延时的偏差导致的阿秒拍频信号的不对称性,和两个双光子信号的最大值分别向相反的方向偏离零延时点的现象.FASPB作为一种阿秒超快调制过程,从理论上说它可以扩展到任何两偶极禁戒跃迁激发态的能级和系统.
关键词:
阿秒和频
极化拍
四能级
双光子 相似文献
25.
Phase dispersion of Raman and Rayleigh-enhanced four-wave mixings in femtosecond polarization beats 下载免费PDF全文
Based on color-locking noisy field correlation in three Markovian
stochastic models, phase dispersions of the Raman- and
Rayleigh-enhanced four-wave mixing (FWM) have been investigated. The
phase dispersions are modified by both linewidth and time delay for
negative time delay, but only by linewidth for positive time delay.
Moreover, the results under narrowband condition are close to the
nonmodified nonlinear dispersion and absorption of the material.
Homodyne and heterodyne detections of the Raman, the Rayleigh and
the mixing femtosecond difference-frequency polarization beats have
also been investigated, separately. 相似文献
26.
Using high-resolution depletion spectroscopy, we have experimentally studied the physics of near-threshold low Rydberg states of all three stable isotopic variants of molecular hydrogen. The experiments were required to calibrate the absolute wavelength, including several transitions from the EF (v = 0) and EF (v = 6 or v = 9) to the same low-n Rydberg states. The measurements have been performed for several initial rotational levels in all three stable isotopic variants. Transitions to very high vibrational levels of the B, Bt, and C states have been measured with accuracy 0.002cm^-1. The pulsed amplifier perturbations were also measured by opticalhe terodyne methods. 相似文献
27.
The dressed four- and six-wave mixings in a V-type four-level system
are considered. Under two different dressed conditions, two- and
three-photon resonant Autler--Townes splittings, accompanied by
enhancement and suppression of wave mixing signal, are obtained
analytically. Meanwhile, an electromagnetic induced transparency of
multi-wave mixing is presented, which shows multiple peaks and
asymmetric effects caused by one-photon, two-photon and three-photon
resonances, separately. The slow light propagation multiple region of
multi-wave mixing signal is also obtained. 相似文献
28.
基于两单光子过程的相位共轭二阶极化干涉,从理论上研究了V型三能级系统在阿秒量级的对称和频极化拍频(SFPB),考虑了抽运光束为窄带线宽或宽带线宽的情形,发现测得的信号对任意带宽的马可夫随机光场的统计特征非常敏感,其在测量偶极禁界跃迁两激发态之间的能级和时并不受激光线宽的限制,仅取决于光学跃迁均匀增宽,而且可以得到消除多普勒增宽的测量精度.在窄带情形下,场关联对SFPB信号影响很弱.在宽带情形下,SFPB信号表现出共振 非共振交叉关联.SFPB作为一种阿秒超快调制过程,从理论上说它可以扩展到任何和频能级系统.
关键词:
阿秒
和频
极化拍
二阶相干 相似文献
29.
Coexisting Raman- and Rayleigh-Enhanced Four-Wave Mixing in Femtosecond Polarization Beats 下载免费PDF全文
Based on the polarization interference of Raman- and Rayleigh-enhanced four-wave mixing processes, heterodyne detection of the Raman, Rayleigh and coexisting Raman and Rayleigh femtosecond difference-frequency polarization beats is investigated in the cw and the three Markovian stochastic models, respectively. These two processes exhibit asymmetric and symmetric spectra, respectively, and the thermal effect in them can be suppressed by field-correlation method. Such studies of coexisting Raman- and Rayleigh-enhanced four-wave mixing processes can have important applications in coherence quantum control, and quantum information processing. 相似文献
30.
薄原子蒸气的双光子Dicke窄化选择反射光谱 总被引:1,自引:0,他引:1
研究了囚禁于两电介质面间的(A)型三能级原子的双光子Dicke窄化选择反射(TDNSR)光谱.通过对不同膜厚及不同抽运光强度的TDNSR线璎的分析,发现由于蒸气中的原子与电介质表面碰撞的消激发效应和薄蒸气膜中的慢原子效应,以及双光子光谱的消多普勒配置,TDNSR线型在很多情形下表现为亚多普勒结构,且线型随 蒸气膜层的厚度与探测光波长的比值呈周期性变化.当L=2mλ/4(m为正整数)时,TDNSR消失.而当2mλ/4< L<(2m 2)A/4时.线型为典型的色散曲线,且L趋近(2m 1)λ/4时对称性增强.精确调谐强抽运光于能级|2>-|3>的跃迁时,在探测光的共振区域△d=0附近,TDNSR极高的变化率表明探测光具有显著的群速变慢效应. 相似文献