Storage of light pulses in Rb vapour with bright Zeeman coherences and the associated enhanced absorption and steep negative dispersion is reported. Our experimental observations are qualitatively similar to the well-known proof-of-principle demonstration of light storage (D F Phillips et al 2001 Phys. Rev. Lett. 86 783), but obtained under conditions where electromagnetically induced transparency (EIT) does not exist and the slow-light dark-state polariton model does not apply. Under the present experimental conditions the retrieved pulses obtained in atomic media with dark or bright Zeeman coherences have very similar exponentially decaying slopes which are independent of the shape of the incoming signal pulse. Numerical modelling based on the optical Bloch equations reproduces the essential features of the experimental observations.Storage of light pulses in Rb vapour with bright Zeeman coherences and the associated enhanced absorption and steep negative dispersion is reported. Our experimental observations are qualitatively similar to the well-known proof-of-principle demonstration of light storage (D F Phillips et al 2001 Phys. Rev. Lett. 86 783), but obtained under conditions where electromagnetically induced transparency (EIT) does not exist and the slow-light dark-state polariton model does not apply. Under the present experimental conditions the retrieved pulses obtained in atomic media with dark or bright Zeeman coherences have very similar exponentially decaying slopes which are independent of the shape of the incoming signal pulse. Numerical modelling based on the optical Bloch equations reproduces the essential features of the experimental observations.

Journal of Physics B Atomic Molecular and Optical PhysicsNov 9, 200519 citations

Remarks on Negative Absorption

Sergey G. Rautian, Igor I Sobel'man

Optics and SpectroscopyJan 1, 19616 citations

Switching from positive to negative dispersion in transparent degenerate and near-degenerate systems

Chana Goren, A. D. Wilson‐Gordon, M. Rosenbluh +1 more

We investigate realistic atomic systems whose dispersion at line center switches from positive to negative and vice versa, as a particular experimental parameter is changed. We concentrate on those systems which have low probe absorption or gain at line center leading to a high figure of merit, and simultaneously have low pump absorption. For this purpose, we study both open and artificially closed ${F}_{g}=\stackrel{\ensuremath{\rightarrow}}{1}{F}_{e}=1$ and ${F}_{g}=\stackrel{\ensuremath{\rightarrow}}{1}{F}_{e}=2$ transitions in ${}^{87}\mathrm{Rb},$ in the absence and presence of an applied magnetic field. We find that the preferred system for observing switchover in the sign of the dispersion from positive to negative, as the pump Rabi frequency increases, is the open near-degenerate ${F}_{g}=\stackrel{\ensuremath{\rightarrow}}{1}{F}_{e}=1$ system. In the presence of Doppler broadening, the dispersion is positive for all realistic experimental parameters. Thus the switchover in the sign of the dispersion is only observable in the absence of Doppler broadening.We investigate realistic atomic systems whose dispersion at line center switches from positive to negative and vice versa, as a particular experimental parameter is changed. We concentrate on those systems which have low probe absorption or gain at line center leading to a high figure of merit, and simultaneously have low pump absorption. For this purpose, we study both open and artificially closed ${F}_{g}=\stackrel{\ensuremath{\rightarrow}}{1}{F}_{e}=1$ and ${F}_{g}=\stackrel{\ensuremath{\rightarrow}}{1}{F}_{e}=2$ transitions in ${}^{87}\mathrm{Rb},$ in the absence and presence of an applied magnetic field. We find that the preferred system for observing switchover in the sign of the dispersion from positive to negative, as the pump Rabi frequency increases, is the open near-degenerate ${F}_{g}=\stackrel{\ensuremath{\rightarrow}}{1}{F}_{e}=1$ system. In the presence of Doppler broadening, the dispersion is positive for all realistic experimental parameters. Thus the switchover in the sign of the dispersion is only observable in the absence of Doppler broadening.

Physical Review AOct 14, 200343 citations

{}^{87}\mathrm{Rb},

in the absence and presence of an applied magnetic field. We find that the preferred system for observing switchover in the sign of the dispersion from positive to negative, as the pump Rabi frequency increases, is the open near-degenerate ${F}_{g}=\stackrel{\ensuremath{\rightarrow}}{1}{F}_{e}=1$ system. In the presence of Doppler broadening, the dispersion is positive for all realistic experimental parameters. Thus the switchover in the sign of the dispersion is only observable in the absence of Doppler broadening.