共查询到16条相似文献,搜索用时 296 毫秒
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本文研究了缀饰原子系统中的双光子共振非简并四波混频.理论上我们研究了多普勒增宽的四能级系统中耦合光场对双光子共振非简并四波混频的影响,发现加入强耦合场后,非简并四波混频频谱出现Autler-Townes分裂;在不同双光子共振失谐时,由于量子干涉双光子共振非简并四波混频的信号能够被抑制或增强.实验上我们在Ba原子蒸汽中,通过引入基态6s2和自电离里德堡态6pnd之间的原子相干证实了该现象.本方法提供了一种不仅可以测得共振频率和横向弛豫,而且可以测得两个高激发原子态之间的跃迁的偶极矩阵元的新的光谱学工具. 相似文献
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光学外差法测量Ba原子的自电离态 总被引:1,自引:1,他引:0
提出了把三光子共振非简并六波混频(NSWM)和双光子共振非简并四波混频(NFWM)应用于研究Ba原子自电离态的光学外差探测方法。采用该方法测量了Ba原子的6P3/219d自电离态,并观察到了三光子共振 NSWM和双光子共振NFWM信号干涉引起的信号增强。该方法是一种纯非线性光学方法,具有优秀的空间分辨率和简单的光路。其中双光子共振非简并四波混频信号作为本地振荡光束,三光子共振非简并六波混频信号作为信号光束,通过 改变信号光束的频率来达到用光学外差探测法研究Ba原子自电离态的目的。该方法中,实现相位匹配所要求的条件不是很严格,可以在很宽的频率范围内实现相位匹配,而一般的六波混频很难做到相位匹配, 并且所测量的信号是相干光, 当用窄带宽的激光时,可以获得消多普勒的分辨率。 相似文献
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理论研究了五能级系统中三光子共振非简并六波混频(NSWM) 由于中间能级加入耦合光场而产生的量子干涉效应. 分析了耦合光场对三光子共振NSWM信号以及频谱的影响. 研究发现, 在强耦合场作用下, NSWM的频谱出现了Autler-Townes分裂, 它反映的是两个缀饰态的能级, 量子干涉可以使NSWM信号被抑制或增强. 提出利用量子干涉对NSWM信号产生增强作用, 可以由耦合场产生的缀饰态代替原子固有能级, 成为三光子共振的中间态, 从而控制耦合场来选择三光子共振的中间态的位置. 相似文献
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在CS2介质中观测到由声波引起的布里渊增强非简并四波混频(NFWM)和由分子取向栅产生的瑞利型NFWM.研究发现,分子取向栅与声波之间并不是相互独立的,声波的存在会破坏瑞利型NFWM和布里渊增强NFWM极化之间的相位关系.
关键词:
四波混频
布里渊散射
瑞利散射 相似文献
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研究了采用双光子共振非简并四波混频技术测量原子里德伯态碰撞展宽时出现的伴线现象, 测量了不同缓冲气压下的钡原子里德伯态6snd 1D2 (n=16, 22, 36) 的四波混频谱线, 研究了伴线随主量子数n 的变化曲线以及伴线信号强度随缓冲气压压强的变化曲线, 分析了伴线对NFWM谱线的线宽的影响, 发现考虑伴线对四波混频谱线线宽的贡献, 可以对NFWM模型下测量到的碰撞展宽系数进行修正. 相似文献
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We discuss the effects of quantum interference in the time-development and spectra of resonant two-photon ionisation where two intermediate states participate. We find general criteria for the formation of stable dressed states immune to photoionisation. 相似文献
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Two-photon resonant nondegenerate four-wave mixing (NFWM) with the
addition of a coupling field in Ba atomic vapour has been studied. We
find that coherence of the atomic level transitions leads to
suppression of the NFWM signal, giving rise to a dip with a linewidth
that is linearly proportional to the intensity of the coupling field. 相似文献
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Optical absorption in asymmetric double quantum wells driven by two intense terahertz fields 下载免费PDF全文
Optical absorption is investigated for asymmetric double quantum wells driven by a resonant terahertz field and a varied terahertz field both polarized along the growth direction. Rich nonlinear dynamics of the replica peak and the Autler-Townes splitting of various dressed states are systematically studied in undoped asymmetric double quantum wells by taking account of multiple factors, such as the frequency of the varied terahertz field and the strength of the resonant terahertz field. Each electron subband splits into two dressed states when the resonant terahertz field is applied in the absence of the varied terahertz field, the optical absorption spectrum shows the first order Autler-Townes splitting of the electron subbands. When a varied terahertz field is added into the resonant system, the replica peak and the second order Autler-Townes splitting of the dressed states near the band edge respectively emerge when the varied terahertz field is non-resonant and resonant with these dressed states. When the strength of the resonant terahertz field is increased, the first order Autler-Townes double peaks and the replica peak in the optical absorption spectrum shift with the shifts of the dressed states. The presented results have potential applications in electro-optical devices. 相似文献
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We report a three-photon resonant nondegenerate six-wave mixing (NSWM) in a dressed cascade five-level system. It has advantages that phase match condition is not stringent and NSWM signal is enhanced tremendously due to the multiple resonance with the atomic transition frequencies. In the presence of a strong coupling field, the threephoton resonant NSWM spectrum exhibits" Autler-Townes splitting. This technique provides a spectroscopic tool for measuring not only the resonant frequency and dephasing rate but also the transition dipole moment between two highly excited atomic states. 相似文献
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We report the observation of dressed states of a quantum dot. The optically excited exciton and biexciton states of the quantum dot are coupled by a strong laser field and the resulting spectral signatures are measured using differential transmission of a probe field. We demonstrate that the anisotropic electron-hole exchange interaction induced splitting between the x- and y-polarized excitonic states can be completely erased by using the ac-Stark effect induced by the coupling field, without causing any appreciable broadening of the spectral lines. We also show that by varying the polarization and strength of a resonant coupling field, we can effectively change the polarization axis of the quantum dot. 相似文献