Reversal of the wave front of light in the case of depolarized pumping

N. F. Andreev, V. I. Bespalov, M. A. Dvoretskii +1 more

Natarajan D. Bhaskar, M. Hou, B Suleman +1 more

We have discovered a novel, spatially propagating wave front which is generated by laser pumping of an optically thick medium to a state of complete transparency. The wave front consists of a moving band of fluorescent light which marks the location of atoms which are being pumped. The wave-front velocity $v$, the photon flux ${I}_{0}$, the atomic number density $N$, and the number $n$ of photons absorbed per atom are related by $v={I}_{0}\ifmmode\times\else\texttimes\fi{}{(\mathrm{Nn})}^{\ensuremath{-}1}$.

D. Grischkowsky, N. S. Shiren, R. J. Bennett

Time-reversed optical wave fronts were generated by degenerate four-wave mixing in rubidium vapor. An extremely large and resonantly enhanced electronic nonlinearity, described by the adiabatic following (AF) model, was responsible for the mixing. The intensity dependence of the AF nonlinear susceptibility was shown to explain the observed reduction in conversion efficiency at high pumping intensities.

Valerii V Ragul'skii

Pavel A Apanasevich, Anatoly A. Afanas'ev, С. П. Жвавый

An analysis is made of reversal of the phase front of an optical beam in four-wave interaction in a resonant medium. Expressions are obtained for the amplitudes of the signal and reversed beams. It is shown that the reversal coefficient does not depend on the sign of the frequency detuning and may be much greater than unity at pump powers not exceeding the saturation power of the resonance transition.

Claude N. Cohen-Tannoudji