共查询到19条相似文献,搜索用时 873 毫秒
1.
研究了两电介质面间级联四能级系统原子的缀饰四波混频(FWM)光谱.在缀饰场的作用下FWM信号可产生Autler-Townes (AT)分裂,分裂所产生的峰及凹陷的线型及缀饰场对FWM信号的抑制与增强效应均受原子极化相干及受限原子与光场相互作用瞬态机制的调制. 相似文献
2.
研究了两电介质面间级联四能级系统原子的缀饰四波混频(FWM)光谱.在缀饰场的作用下FWM信号可产生Autler-Townes (AT)分裂,分裂所产生的峰及凹陷的线型及缀饰场对FWM信号的抑制与增强效应均受原子极化相干及受限原子与光场相互作用瞬态机制的调制. 相似文献
3.
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
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从理论上研究了N5B五能级系统中一个激光场重复缀饰四波混频过程.结合能级图分析,从它特殊的Autler-Town分裂峰中可以非常清晰地看出其重复缀饰的作用.还研究了在强Probe场和强耦合场下N5B五能级下缀饰四波混频信号的抑制增强现象.采取独特的处理方法——独立作用法,研究结果表明一个激光场作用于N5B五能级系统时存在两次缀饰,并形成缀饰能级的二重分裂或者三重分裂,不同于多个耦合场对原子的多重缀饰作用.应用于非线性光谱术中对多峰结构的研究.
关键词:
四波混频
电磁感应透明
重复缀饰 相似文献
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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
9.
在一个非简并三能级梯型原子系统中,通过调谐探测场的强度,从理论和实验上研究了探测场通过铷原子蒸气的传输谱线。当探测场不再足够弱时,通过缀饰微扰链的方法推导了探测场响应的表达式并预言了电磁诱导吸收(electromagnetically induced absorption, EIA)的存在。实验上,在室温铷原子的D2线中,当弱探场状态切换到强探测状态时,不局限于单光子共振条件,电磁感应透明(electromagnetically induced transparency, EIT)向EIA的转换在探测场的不同失谐量处被实现。利用缀饰能级图分析了强的探测场和耦合场产生的二级缀饰态之间的相长干涉是EIA形成的主要原因。由于EIT和EIA的许多应用依赖于共振附近的异常色散,这个结果引入了控制色散符号的新能力。 相似文献
10.
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
11.
Nonlinear selective reflection spectroscopy of V‐type atomic system at the gas‐solid interface
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Tengfei Meng Zhonghua Ji Dianqiang Su Yanting Zhao Liantuan Xiao Suotang Jia 《Annalen der Physik》2016,528(6):512-518
We theoretically present the nonlinear selective reflection spectroscopy of V‐type atomic system at gas‐solid interface in a pump‐probe scheme. The saturation and coherence effects are distinguished by solving Liouville equation in the absence and presence of reduced density matrix element between the two excited levels. When the coherence effect exists, two peaks appear in reflection spectroscopy with asymmetry lineshape. We investigate the dependence of reflection spectroscopy on pump field intensity, frequency detuning and coherent decay rate induced by collision between atoms. The lineshape can be explained based on reflection spectroscopy contributed from atoms with negative (before collision) and positive (after collision) velocities, single‐photon and two‐photon processes. This study is helpful for investigating quantum coherence and dynamic processes of atoms at gas‐solid interface. 相似文献
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The zero-field level crossing effect in selective reflection from an atomic vapour is calculated for normally incident radiation using a theory which, unlike the conventional dispersion theory, includes the effect of transient polarization behaviour due to diffuse wall collisions of vapour atoms. Both longitudinal and transverse magnetic fields are considered. At low vapour densities we find a narrowing of the level crossing curve in selective reflection relative to its width in the conventional dispersion theory. The narrowing is calculated as a function of the ratio of the homogeneous and inhomogeneous line width of the vapour for a Maxwellian velocity distribution of the vapour atoms and spectrally uniform incident radiation. The theory of this paper offers an explanation for recent observations of narrowing of level crossing curves in selective reflection. 相似文献
13.
Selective reflection combined with Fabry--Perot effects from two-level atoms confined between two dielectric walls 总被引:1,自引:0,他引:1
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The coefficient of selective reflection at oblique incidence from two-level
atoms confined between two dielectric walls is calculated in this paper.
It is found to
be related to the transient behaviour of atoms after colliding with the wall
and the distribution of the field inside the vapour corresponds to L /
\lambda , with L the thickness of the film and \lambda the incident
wavelength. We find that the sub-Doppler structure is manifest both for
normal incidence and small angle oblique incidence. It is feasible to detect
the real part of selective reflection in several cases that have not been
achieved before. 相似文献
14.
H. Li T.S. Varzhapetyan V.A. Sautenkov Y.V. Rostovtsev H. Chen D. Sarkisyan M.O. Scully 《Applied physics. B, Lasers and optics》2008,91(2):229-231
We have studied the selective reflection from the interface between a dense rubidium (Rb) atomic vapor and a transparent dielectric.
A remarkable narrowing of the spectrum, which can be used to improve the resolution of spectroscopy of dense media, has been
demonstrated. This narrowing results from the reduction of the dipole–dipole interaction between atoms when the Rb vapor is
excited by a strong pump laser. By using this technique, we have resolved the hyperfine structure of the Rb D2 line, which is hidden by collisional broadening.
PACS 32.70.Jz; 42.50.Ct; 34.80.Dp 相似文献
15.
A. D. Sargsyan A. S. Sarkisyan D. H. Sarkisyan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2018,53(4):301-312
The effect of the van der Waals interaction of cesium atoms with the sapphire windows of a nanocell was experimentally investigated using the selective reflection process. The distance L between the windows varied in the range of 50–2000 nm and the nanocell was filled with the vapors of cesium atoms. For the Cs atoms (the transition 6S1/2 → 6P1/2), the C3 coefficient of the van der Waals interaction with the sapphire windows of the nanocell is measured. It is shown that it is possible to determine the magnetic fields with the spatial resolution of 70 nm using the selective reflection spectrum and, consequently, both the homogeneous and highly gradient magnetic fields can be measured. 相似文献
16.
《Laser \u0026amp; Photonics Reviews》2017,11(6)
Metasurfaces, the phase‐engineered quasi‐2D interfaces, have attracted intensive interest due to their great capabilities in manipulating the reflection, refraction and transmission of electromagnetic waves. Here, we demonstrate the design and realization of a gradient chiral metamirror tailored for spin‐selective anomalous reflection based on the theory of Pancharatnam‐Berry phase. Asymmetric split ring resonators are employed as the basic meta‐atoms for strong circular dichroism. Dispersionless phase discontinuities are achieved by adjusting the orientation of the meta‐atoms, and spin‐dependent absorption is realized by introducing a chiral resonance. Theoretical results predict both broadband beam deflection and spin‐selective absorption for circularly polarized waves in a designer metamirror. Experimental verification of this bifunctional performance is implemented at microwave frequencies and the measured results agree well with the simulation ones. Such chiral metamirrors could pave an avenue towards spin‐selective modulation of the wavefront and might find promising applications in planar electromagnetic devices. 相似文献
17.
Dicke-Narrowing Spectroscopy of Doubly Dressed Electromagnetically Induced Transparency and Singly Dressed Four-Wave-Mixing in a Confined Atomic System
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Dicke-narrowing effect appears both in doubly dressed electromagnetically induced transparency and singly dressed four-wave-mixing lines due to the contribution of slow atoms resulting from de-excited effects of atom-wall collision and transient behaviour of atoms in a confined system. A robust recipe for high resolution spectroscopy of electromagnetically induced transparency dressed by two fields and four-wave-mixing lines comparable with the cold atoms is achievable in a thin vapour cell in experiments. 相似文献
18.
A. Ch. Izmailov 《Laser Physics》2007,17(12):1374-1377
We propose the new highly sensitive method of sub-Doppler laser spectroscopy based on the selective record of anisotropic flows of ions, which are formed as a consequence of the photoionization of atoms (molecules) of a rarefied gas in a cell after their resonance excitation by running monochromatic radiation. This method of photoionization spectroscopy may be used for the receipt of spectroscopic data on atoms (molecules), for the detection of individual atoms, and for isotope (isomer) separation in a gas cell. 相似文献
19.
Dressed Four-Wave Mixing Spectroscopy Modified by Polarization Interference and Atom-Wall Collision in Micrometric Thin Cells
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Dressed four-wave mixing (DFWM) spectroscopy is investigated theoretically in some micrometric thin cells. It is found that DFWM spectra can be modified by polarization interference of atoms and transient effects induced by atom-wall collision. This modification can lead to width-narrowing of DFWM lines and facilitates to implement experiment of high resolution DFWM spectroscopy in a confined atomic system. 相似文献