Propagation of light in a Dense Medium

B. V. Ermakov, Yu A Il'inskiĭ

К. А. Баранцев, A. N. Litvinov, Evgeniy Popov

This work is devoted to nonlinear effects in the atomic medium excited by multifrequency laser radiation. We have considered collective light scattering in the optically dense medium in conditions of coherent population trapping. Propagation of intermode correlation coefficient was calculated and it was found that correlation can increase in the medium. Light shifts of the coherent population trapping resonances and ways of their suppression were analyzed. Propagation of radiation in the medium with closed excitation scheme was investigated.

B. A. Samson, Wojciech Gawlik

Counterpropagation of two light beams in a resonant medium so dense that the local driving field differs from the external field is considered. It is shown that efficient energy transfer between the two beams occurs if there is some asymmetry between their propagation conditions due to, e.g., their frequency difference or Doppler detuning caused by the motion of the medium. The directional energy flow may predominate over absorption and lead to gain.

Nicolai G. Basov, Vladilen S Letokhov

Yu. A. Vdovin, V. M. Ermachenko

Li You, J. Cooper

We study the propagation of a near-resonant strong laser light with a broad background continuum spectrum in a dense gaseous two-level medium. Due to the nonlinear saturation caused by the driving of the coherent component of the field, spectral regions close to the Rabi sidebands with significant gain exist close to the resonance. The subsequent evolution of the spectrum of the propagating field displays interesting features, and in the stationary limit a broadening of the spectral line always eventually happens in the end which contradicts the coherent narrowing phenomenon for pulsed propagation. This may shed some new light on the mechanisms of cone emission.