RADIATION TRAPPING IN AN ALKALI-VAPOR-NOBLE-GAS MIXTURE EXCITED BY A STRONG LASER-PULSE

We analyze the nonlinear, non-stationary radiation trapping process in a cell filled with a noble gas and an alkali vapor excited by a shea intense laser pulse. We derive analytical approximations for the total density of the excited atoms, and for the radiation emerging from the cell. The considered lineshapes are pure Doppler, Voigt, and pure Lor entzian profiles. We confirm that the emergent radiation can decay fas ter than with the natural lifetime of the atomic transition. We also s how that as we increase the, noble gas pressure, the decay of the emer gent radiation becomes slower at early times and faster at late times.