Origin of the sub-natural line-narrowing effect in resonance fluorescence

Boris Kryzhanovsky, A. O. Melikyan

G. Nikogosyan, David G. Sarkisyan, Yu. P. Malakyan

The features of resonance fluorescence and absorption of resonance laser radiation in atomic vapors in a superthin cell with thickness L of the order of a wavelength lambda are investigated theoretically. Taking into account the Fabry-Perot interference effect, it is found that the dependence of the fluorescence and absorption spectra on the ratio L/lambda is substantially different. Coherent spectral narrowing - the Dicke effect - when L=(2n+1)lambda/2 and broadening of the spectral line when L = n lambda (n is a whole number) are observed in the absorption spectra. This effect is absent in the spector of resonance fluorescence in extended media. It is also shown that the processes of saturation and optical pumping significantly alter the spectral line shape as the laser intensity increases; in particular, additional sub-Doppler dips appear at the frequency of the atomic transitions. Calculated curves are given for the D2 lines of ^85Rb atoms. © 2004 Optical Society of America

Serge Reynaud, Claude N. Cohen-Tannoudji

S. Gateva, Emilia A. Alipieva, Elena T. Taskova

The investigation of the coherent-population-trapping (CPT) resonance on the degenerate two-level system of the $({F}_{g}=2\ensuremath{\rightarrow}{F}_{e}=1)$ transition of the $^{87}\mathrm{Rb}\phantom{\rule{0.3em}{0ex}}{D}_{1}$ line by means of a Hanle effect configuration in an uncoated vacuum cell [Opt. Lett. 28, 1817 (2003)] has shown that the measured in fluorescence resonance has a complex shape---a very narrow (about 1 mG) structure superimposed on a broader one (about few tens of mG). In this work, the dependence of the width and amplitude of the CPT resonance structures are measured at different laser power densities when the registration is in fluorescence and transmission. While the narrow resonance width does not change within the limits of the accuracy of our measurements, the wide resonance width dependence is complex and is different in fluorescence and transmission. The origins of the observed resonance width narrowing of the CPT resonance structures registered in fluorescence and transmission are discussed.

Nathan C. Pixley, Tiffany L. Correll, Dimitri Pappas +3 more

A cesium-based resonance fluorescence monochromator with a spectral resolution of 200 MHz and a tunable response over the D(2) absorption line of cesium (380 MHz) is described. The narrow spectral response is achieved through excitation of a monokinetic population of the 6(2)P(3/2)( degrees ) state by arrangement of the excitation lasers in either a copropagating or a counterpropagating orientation. The narrow spectral response of the detector allows for excitation of specific hyperfine components involved in the 6(2)P(3/2)( degrees ) (F=3-5) to 6(2)D(5/2) (F=2-6) transition (917.23 nm). The selectivity gained through resolving specific hyperfine transitions allows for a photon detector that is both spectrally tunable and narrow. We report the sub-Doppler linewidths achieved through various laser beam orientations. We also describe how these beam geometries can be applied to spectrally narrow and tunable image detection.

V. E. Lembessis