Pulsed resonant laser interaction in three level systems

Donna Maree Sheppard

R. Netz, Thomas Feurer, J. A. Fülöp

We present a detailed study of the interaction of ultrashort laser pulses with a resonant three level system (fine structure levels of rubidium). As expected, for low intensities a linear model and for higher intensities a semiclassical model (Maxwell-Bloch) is fully sufficient to describe the observed results. In both cases, however, it is essential to have an accurate knowledge of the incident electric field, i.e., the amplitude and the phase, in order to simulate the interaction process. It is shown that on small time scales the phase modulation of the incident pulse influences the reshaping process during pulse propagation whereas on longer time scales the reshaping is solely governed by the dynamics of the atomic system.

Zhenzhong 振忠 Ren 任

Abstract The population transfer of sodium in a single analytical laser pulse was studied in three models: two-level sodium, three-level sodium and many-level sodium. The effect of a third state on a two-level system was studied by investigating a ladder three-level system. Two effects were found in the vicinity of the resonance frequency.

Leonid A Bol'shov, Anatoly P. Napartovich

John A. Benda, Daniel J. Gauthier, Robert W. Boyd

Resonantly enhanced sum-frequency generation of pulsed laser radiation is treated theoretically for the case of a three-level system. The density-matrix equations of motion are solved using second-order, time-dependent perturbation theory with the inclusion of transient effects. The energy and spectrum of the generated radiation are calculated as functions of laser detunings, laser pulse lengths, and temporal overlap of the laser pulses. The tuning characteristics and output pulse characteristics are found to differ qualitatively depending on whether or not the excitation pulses satisfy the adiabatic following criteria generalized for the case of a three-level atom.

W. Forysiak