Narrowing of the Doppler Width in a Standing Wave

Natalia G. Bykova, L. E. Grin', Valentina V. Lebedeva +1 more

B. J. Feldman, Michael S. Feld

L. A. Budkin, V. V. Mityugov, A. I. Pikhtelev +1 more

G. Grynberg

We describe the influence of the intensity variation of the light in a standing wave on the lineshape of a Doppler-free multi-photon transition. We show that as long as the light shifts and the saturation are small compared to the Doppler width, a motional narrowing effect occurs and the line remains Lorentzian, the centre being shifted by an amount equal to the mean value of the dynamic Stark effect. We consider also the case of transients. We show that at resonance, it is possible to observe different responses according to the light intensity. In particular, it is possible to observe Rabi oscillations only if the Rabi frequency is larger than the natural width and smaller than the Doppler width of the transition.

Vladilen S Letokhov, V. P. Chebotaev

The review deals with resonance phenomena resulting from saturation of low-pressure-gas absorption lines by a coherent optical field, when the spectral lines are inhomogeneously broadened by the Doppler effect. Principal attention is paid to narrow resonances of width much smaller than the Doppler widths, which are produced upon saturation of the absorption by light waves under various experimental conditions (inside and outside the laser resonator, in traveling and standing waves, in spatially separated waves, etc.), owing to different effects (absorption saturation, mode interaction in the laser). Each of the phenomena is considered from both the theoretical and the experimental points of view. The phenomena considered serve as a basis of a new branch of optical spectroscopy, namely nonlinear laser spectroscopy of ultrahigh resolution.

Sergey Borisenok, Yu. Rozhdestvensky, Аlexander L. Fradkov +2 more

Dynamics of cold atoms in laser standing wave is a subject of a great interest, stimulated by the main problem of nano-lithography with cooled atoms: We can obtain the very narrow width of cooled atoms, much less than wavelength of optical radiation, by focusing in standing wave. We consider the possibility to increase the efficiency which means obtaining the very narrow width of atoms by focusing all atoms of an initial atom beam by controlling of an atom dynamics in periodic potential of standing wave. Such control for cooled atom dynamics achieves by using the additional laser field. There are two additional possibilities of atom focusing to comparing with usual focusing without control function. The first, the control function was chosen so that all atoms fall into potential wells of standing wave. In this case we obtain the increasing of atom number in five times (compare with ordinary focusing). At the same time, the width of atom distribution function inside wells is about /spl lambda//20. In the second case, the control function was chosen so that all atoms prepare on the hills of the periodical potential. For such unusual focusing we demonstrate that the width of atoms can be done extraordinary narrow 6 nm and an atom number increases in one hundred times.