Stability theory of coherent laser pulses in an inverted medium

С. В. Сазонов

Paul R. Gerber, M. B�ttiker

Lee M. Frantz, John S. Nodvik

The growth of a radiation pulse traversing a medium with an inverted population is described by nonlinear, time-dependent photon transport equations, which account for the effect of the radiation on the medium as well as vice versa. The equations are solved in closed form for an arbitrary input pulse and an arbitrary initial distribution of inverted population. The solutions are discussed in detail for the particular cases of a square pulse and a Lorentzian pulse, both with a uniform initial population inversion.

Filippo Caruso, I. Herrera, Saverio Bartalini +1 more

We investigate the propagation of a coherent probe light pulse through a three-level atomic medium (in the Λ-configuration) in the presence of a pump laser under the conditions for gain without inversion. When the carrier frequency of the probe pulse and the pump laser are in a Raman configuration, we show that it is possible to amplify a slow propagating pulse. We also analyze the regime in which the probe pulse is slightly detuned from resonance where we observe anomalous light propagation.

Leonid A Bol'shov, Vladimir V. Likhanskii, Anatoly P. Napartovich

Petr P Vasil'ev

An analysis is made of the conditions for the generation of superfluorescence pulses in an inverted medium of electron—hole pairs in a semiconductor. It is shown that strong optical amplification in laser semiconductor amplifiers characterised by α L ≫ 1 (α is the small-signal gain and L is the amplifier length) leads to suppression of phase relaxation of the medium during the initial stages of evolution of superfluorescence and to formation of a macroscopic dipole from electron—hole pairs. Cooperative emission of radiation in this system results in generation of a powerful ultrashort pulse of the optical gain, which interacts coherently with the semiconductor medium. It is shown that coherent pulsations of the optical field, observed earlier by the author in Q -switched semiconductor lasers, are the result of superfluorescence and of the coherent interaction between the optical field and the medium.