Analytic Study of Pulse Chirping in Self-Induced Transparency,

Ljubomir Matulic, Joseph H. Eberly

Ljubomir Matulic

Miguel Orszag, R. Ramirez

Ljubomir Matulic

Gagik P. Djotyan, G. Demeter, Jozsef S. Bakos +3 more

This paper shows that a single laser pulse with a chirped frequency can generate trapped superposition of the ground states in the /spl Lambda/-atom when the width of the transform-limited laser pulse envelope frequency spectrum (without chirp) is smaller but the peak Rabi frequency of the pulse is larger than frequency interval between the two ground states of the /spl Lambda/-atom. This study also analyzes the propagation of the frequency-chirped laser pulse in a medium consisting of /spl Lambda/-atoms analytically and by exact numerical solution of coupled Bloch-Maxwell equations. The results show that there is nearly absorptionless propagation of the single frequency-chirped laser pulse on distances more than 40 times the pulse duration, when the formulated above conditions of negligible excitation of the /spl Lambda/-atom are fulfilled. The described effect of absorptionless propagation of the single frequency-chirped pulse is referred to as electromagnetically self-induced transparency.

Carlos R. Stroud, C. M. Bowden, L. Allen

Resonant absorbing media having many atoms within a cubic resonance wavelength can exhibit large frequency chirps in pulse propagation due to dipole-dipole interactions among the atoms. Analytic solutions are obtained for invariant pulse propagation in such a medium consisting of interacting two-level atoms. Departures from the McCall-Hahn results include nonhyperbolic secant pulse shapes and different than 2π-area pulses. In addition, the excitation of the medium is comparatively suppressed for the same group velocity. The results are interpreted to suggest new experiments.