Zeeman coherance

The non-diagonal submatrices j j>p and j>j p describe the optical coherences between the magnetic sublevels of the states J" and J. The submatrices j j"P and j>j>p describe the particles on levels J" and J respectively. Their diagonal elements characterize the populations of the respective sublevels M" and M, whilst the non-diagonal elements describe the Zeeman coherences. 

Mlynek, J., Drake, K.H. and Lange W. (1979). Observation of transient and stationary Zeeman coherence by polarization spectroscopy, Proc. IV Intern. Conf. Optical Sciences, Tegemsee.—Berlin Springer, pp. 616-618. 

If the ojjtical field that excites atoms or molecules is strong enough, it can create Zeeman coherences not only in the excited state of atoms or molecules, but also in the ground state. In a slightly different context this effect for the first time was studied as an optical pumping of atomic states. 

Figure 20. The effect of optical and Zeeman coherence on the Faraday rotation (theory).

From the data displayed in Fig. 4 we can derive a rate constant YVCC for VCC and a rate constant Yc for collisions destroying the Zeeman coherence Theory predicts that the asymptotic slope of the FM-RHS yields Yc whereas the initial slope of the AM-RHS gives Yycc fitting our experimental data, the rate constants or equivalently, the corresponding collisional cross sections and oan be determined (see... 

Fig. 5.a) Experimental scheme EOM, electrooptic modulator B, static tranverse magnetic field X/4, retardation plate inserted with one of its main axes parallel to the polarization of the probe field , polarization analyzer PD, photodetector, b) Modulated excitation process of Zeeman coherence for the Zeeman-split J=1-J =0 transition of Sm. c) Detection process showing the induced Raman sidebands, d) Schematic of the Doppler distribution indicating the velocity selectivity of the optical excitation and detection of sublevel coherence. 

Ramsey s method for the observation of narrow radiofre-guency (rf) resonances is well known from atomic and molecular beam experiments . In this contribution, we demonstrate the occurence of similar Ramsey resonances in an atomic vapor due to collisional velocity diffusion of sublevel coherence within an optical Doppler distribution. This new phenomenon is observed using coherent resonance Raman processes to optically induce and detect Zeeman coherence in the Sm A=570.7 nm J=1-J =0 transition. 

In the experimental configuration shown in Fig. 5a, counterpropagating laser fields are used for the coherent excitation and phase-sensitive detection of oscillating Zeeman coherence. For a nonzero laser detuning with respect to the... 

A. Nottelman, C. Peers, W. Lange Inversionless amplification of picosecond pulses due to Zeeman coherence. Phys. Rev. Lett. 70, 1783 (1993)... 

Weis, A., Sautenkov, V., and Hansch, T. (1992). Observation of ground-state Zeeman coherences in the selective reflection from cesium vapor. Phys. Rev. A, 45 7991 - 7996. 

DOPPLER NARROWING AND COLLISION-INDUCED ZEEMAN COHERENCE IN FOUR-WAVE LIGHT MIXING... 

During the past year we have replaced the Coherent Model 599-03 by the Coherent Model 599-21. With both dye lasers actively stabilized in frequency, the instrumental resolution could be increased to 1 or 2 MHz. Although the system has not yet operated according to specifications, we have obtained new quantitative data on the linewidth of the central components. It is the purpose of this paper to present these new data. They demonstrate the phenomena of colli-sional narrowing of residual Doppler broadening in four-wave light mixing, as discussed in section 2, and of collision-induced Zeeman coherences, treated in section 3. 

Zeeman coherences in degenerate four-wave light mixing were explicitly considered previously by Steel, Lam and McFarlane. ... 

Fig. 7. Zeeman splitting, in an external magnetic field of 10 gauss, of the four-wave mixing resonance in the geometry of Fig. 1, caused by collision-induced Zeeman coherences with Am = 1.

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