Theory of Radiative-Stark Mixing

Chen-Yu Tai, Robert T. Deck, Charles Kim

We report on an ac-Stark-effect-enhanced wave-mixing experiment in ${\mathrm{I}}_{2}$ vapor in which an output uv signal at frequency 2${\ensuremath{\omega}}_{1}$+${\ensuremath{\omega}}_{2}$ is maximized when the input frequencies ${\ensuremath{\omega}}_{1}$ and ${\ensuremath{\omega}}_{2}$ are both detuned in the same direction from the resonance frequencies of the free molecule. A theory based on a configuration interaction between the ``dressed molecular levels'' is presented to explain the strong enhancement of the uv signal under these conditions. The data presented demonstrate that tunable coherent radiation at ultraviolet and vacuum-ultraviolet frequencies can be generated by the wave-mixing process we describe.

D. T. Pegg

T Zalialiutdinov, Dmitry A. Solovyev, L Labzowsky

Abstract The precise calculations of blackbody radiation (BBR)-induced Stark shifts and depopulation rates for low-lying states of a helium atom with the use of the variational approach are presented. An effect of the BBR-induced Stark-mixing of energy levels is considered. It is shown that this effect leads to a significant reduction in the lifetimes of helium-excited states. As a consequence, the influence of the Stark-mixing effect on the decay rates of metastable states in helium is discussed in the context of formation processes of the cosmic microwave background.

R. Abrams, Avigail Yariv, P. Yeh

Application of dc electric field to a gaseous system destroys the basic inversion symmetry and allows three-wave mixing processes to occur. A theoretical derivation of this effect under conditions of resonantly enhanced nonlinearities is given for a three-level system. Calculations are presented for mixing of a CO2laser with 4-GHz microwaves in the molecule NH2D, producing single lower sideband radiation.

E. Ficocelli Varracchio