Role of collective processes in the absorption of an external laser field in two-level media

Г. М. Ермолаева, В. А. Смирнов, В. Б. Шилов

This paper discusses how the degree of coherence of intense resonance radiation affects the evolution process of collective photoinduced luminescence, which determines the absorption-emission dynamics in concentrated molecular systems. It is shown that the partial breakdown of coherence reduces the radius of the volume in which effective collective interaction occurs in the field-matter system and in which the relative role of classical mechanisms in the absorption-emission cycle increases.

Stephen J. Smith

Stig Stenholm

T. Yu. Golubeva, Yu. M. Golubev, Sergey V. Fedorov +3 more

The Heisenberg-Langevin equation for a spatial laser soliton in a wide-aperture laser with saturable absorption is constructed within the framework of consistent quantum electrodynamics. We discuss in detail the canonical variables for the generation field and the material two-level medium, consisting of centres providing amplification and absorption. It is assumed that laser generation evolves in time much more slowly than an atomic media. This assumption makes it possible to apply the adiabatic approximation and construct a closed equation for the amplitude of a laser field. Much attention is paid to the formulation of Langevin sources when deriving the equation since they play a decisive role in the formation of solitons' quantum statistical features. To provide an appropriate procedure for observing the quantum squeezing of a soliton, synchronization of laser generation by an external weak electromagnetic field is considered. Here we also present the results of the analysis of a classical laser soliton (neglecting the quantum fluctuations), which serves as the basis for further consideration of quantum effects.

T. Yu. Golubeva, Yu. M. Golubev, Sergey V. Fedorov +3 more

Abstract The Heisenberg–Langevin equation for a spatial laser soliton in a wide-aperture laser with saturable absorption is constructed within the framework of consistent quantum electrodynamics. We discuss in detail the canonical variables for the generation field and the material two-level medium, consisting of centres providing amplification and absorption. It is assumed that laser generation evolves in time much more slowly than an atomic media. This assumption makes it possible to apply the adiabatic approximation and construct a closed equation for the amplitude of a laser field. Much attention is paid to the formulation of Langevin sources when deriving the equation since they play a decisive role in the formation of solitons’ quantum statistical features. To provide an appropriate procedure for observing the quantum squeezing of a soliton, synchronization of laser generation by an external weak electromagnetic field is considered. Here we also present the results of the analysis of a classical laser soliton (neglecting the quantum fluctuations), which serves as the basis for further consideration of quantum effects.

F.F. Körmendi