共查询到19条相似文献,搜索用时 93 毫秒
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本文应用量子电动力学理论,研究了强度依存耦合的二能级原子与单模光场相互作用系统中,光场强度对原子共振荧光的影响.证明了系统的共振荧光仍有三峰带结构,光场强度的增加,将使三峰带结构更加明显,但当光场强度很大,使得本征谱分裂值等于一个激光光子能量时,三峰带结构变为双峰带结构,而且边峰带由单光子跃迁变为双光子跃迁. 相似文献
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小颗粒金属表面吸附原子的荧光和共振荧光 总被引:2,自引:2,他引:0
本文使用表面修饰的光学布洛赫方程和镜象法,对小颗粒金属表面吸附原子的荧光和共振荧光等光学特性进行理论研究.着重讨论吸附原子的自发辐射寿命、跃迁频移、共振荧光谱、偶极矩的压缩以及吸收线宽等,研究小颗粒金属的尺寸效应以及吸附原子与它之间距离的变化对上述光学性质的影响. 相似文献
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本文用缀饰原子本征态的方法,导出三原子体系合作共振荧光过程的主方程。求出了共振荧光的谱线结构,各谱线的权重比及各谱线的弛豫速率。文中报道了三原子共振荧光由七条谱线组成,每条谱线又有自己的精细结构。作者认为各谱线的分裂原因在于缀饰原子偶极矩之间的相互耦合。 相似文献
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本文用缀饰原子方法研究了单模激光场驱动下的两能级原子系统的共振荧光.通过在主方程中唯象地引入激光模的激发项补偿散射过程,使该模式中光子数减少.得到了主方程的定态解.并由此得到了共振荧光谱的强度分布及谱线形状. 相似文献
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讨论了强相干激光场驱动下的内腔三能级原子的共振荧光谱,与自由空间情况相比,内腔谱从共振峰为中心向内压缩或向外扩张,但谱线的线型,线宽和强度没有变化,共振峰的线型取决于原子与驱动场之间的失谐程度,文中还谱线特征的形成原因作了分析。 相似文献
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With the concept of negative photon and the K-photon J C model, we investigate analytically the effect of virtual photon field on the collapse revival effect of atomic inversion and squeezing of atom, we find that there is a significant effect of virtual photon field on atomic inversion and squeezing of atom; with the one-photon model as an example, we find that the squeezing of atom occurs periodically, the time and times of squeezing are only related to the resonance frequency and the amplitude of squeezing related to coupling constant of atom field, mean photon number and resonance frequency; also we show that the effect of squeezing of atom does not exist within rotating wave approximation if K≥3. Taking the approach of nearest-neighboring spectrum in the quantum chaos field, we investigate the properties of energy spectrum in one-photon JC model and show that the integrable region,non-integrable region and transition region of this system can be illustrated by a phase diagram;also we discuss the influence of interaction of atoms on spectrum and Δ3 statistics of adjacent energy levels, we find that the influence of interaction is little obvious in strong field but takes great important role in weak field. 相似文献
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The two-photon absorption resonance that is due to the internal charge-transfer transition of an organic push-pull molecule has been characterized. A nonlinear absorption spectrum of the 4-(diethylamino)- beta-nitrostyrene molecule was measured in a tetrahydrofuran solution by optical Kerr ellipsometry. The shape and the amplitude of the two-photon absorption spectrum are well described by a model that uses the relevant one-photon absorption spectrum related to the internal charge-transfer transition. 相似文献
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Constantine Mavroyannis 《Optics Communications》1978,26(3):453-456
The excitation spectrum of a two-level atom interacting with a strong electromagnetic field is considered when the atomic transition frequency is nearly twice the frequency of the laser field. The spectral function consists of four Lorentzian lines describing: the central line peaked near the two-photon resonance, two sidebands peaked at the high and low frequency regions respectively and the one-photon frequency mode. In the limit of high photon densities, the low frequency photon mode is induced by the pump field which removes the singularity occurring at the two-photon resonance frequency. 相似文献
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A theoretical model is proposed to interpret the continuous transition from a resonance fluorescence spectrum to a resonance Raman spectrum, recently observed when the scattering molecule is progressively perturbed by its environment. An analytical expression for the resonant scattering tensor is given, which describes the evolution of the resonance fluorescence spectrum of a diatomic molecule perturbed by a foreign gas. The variations of the intensities and polarizations are quantitatively studied in the case of iodine, and it is shown how the resonance fluorescence spectrum is progressively transformed into a resonance Raman spectrum when the pressure of the perturbing gas is increased. 相似文献
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The absorption of a resonant coupling laser driving a closed degenerate two-level system in an atomic cesium beam was investigated as a function of the detuning of a second laser probing the same transition. The measurements were performed for four different polarization combinations of the two laser beams. Except for the beams of counterrotating polarizations all coupling-laser absorption profiles showed "absorption within transparency," i.e., the absorption in the region around the two-photon resonance was smaller than the absorption corresponding to the one-photon transition induced by the coupling laser, and an extra absorption peak was observed on this curve at the two-photon resonance. With regard to the beams of counterrotating polarizations we observed a switch from absorption within transparency to "transparency within transparency" when the probe-laser power exceeded the constant coupling-laser power. In other words, the cesium ensemble became mostly transparent to the coupling-laser beam at the two-photon resonance. 相似文献
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利用Jaynes-Cummings(缩写为J-C)模型研究了失谐情况下强相干光的长时间挤压行为,其中原子与光场的作用包括单光子跃迁和双光子跃迁两种情况。给出大N极限下挤压度的解析表达式。研究结果表明:对单光子跃迁,失谐(非共振)时的挤压行为定性上与共振时相似,小的失谐对挤压只有小的影响,双光子跃迁时情况不同,失谐起着重要作用。共振时不出现挤压,失谐时才出现挤压,被压缩的不确定度准周期地出现极小,在大N极限下,此极小值系列并趋于零。 相似文献
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Measurements of two-photon fluorescence (TPF) in a CdS crystal using a dye laser pumped by a Q-switched ruby laser are reported. The TPF is measured as a function of source intensity and wavelength. The total fluorescence shows linear and non-linear dependence on the source intensity; from these measurements the TPF part is determined. The measured transition of the crystal's fundamental gap is 2.5 ± 0.02 eV and another forbidden one-photon but allowed two-photon transition is found at 3.24 ± 0.02 eV. 相似文献