Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Soviet Journal of Quantum Electronics

Three-mode emission from a gas laser. I. Stability of steady-state symmetric emission

V. M. Ermachenko, V K Matskevich

Published Sep 30, 1975• 5 citations
Publisher

Abstract

The polarization of the active medium of a three-mode gas laser is calculated allowing for depolarizing atomic collisions and for the active level degeneracy. The calculations are carried out to terms of the third order in the field. The expressions obtained are used to explain some of the published experimental results.
DOI
10.1070/qe1975v004n09abeh011462

Related papers

Competition between high-intensity modes of different polarizations in a gas laser

I. V. Evseev, V. M. Ermanchenko, V K Matskevich

A theoretical analysis is made of the stability range of stimulated emission of two modes with orthogonal and parallel polarizations. The case of transitions between active levels of momenta ja = jb = 1 in a relatively strongly excited medium is considered. It is found that, in contrast to the case of parallel polarizations, emission of two modes with orthogonal polarizations is possible even when the mode spacing is small. Investigation is made of the influence of the quadrupole polarization of the medium on the width of the two-mode emission range. It is shown that the results obtained by calculating the polarization of the medium to within terms cubic in respect of the field amplitude describe correctly relatively highly excited active media.

Soviet Journal of Quantum Electronics•Nov 30, 1976•1 citation

Interaction of modes emitted due to adjacent transitions in gas lasers

Yu. A. Vdovin, I. V. Evseev, V. M. Ermachenko +1 more

A theoretical investigation is made of the feasibility of simultaneous laser action due to adjacent transitions in atoms of a gaseous medium with level momenta j/sub b/..-->..j/sub c/ and j/sub b/..-->..j/sub a/. In the case of small relative excesses of the population inversions of the active levels over the threshold, an expression is derived for the region of simultaneous laser action with parallel and orthogonally polarized fields. The limiting cases of homogeneously and inhomogeneously broadened lines are studied. Calculations are made allowing for depolarizing atomic collisions. For a homogeneously broadened line and negligible degeneracy of the levels, a region of simultaneous laser action is found for an arbitrary relative excess of the population inversion over the threshold.

Soviet Journal of Quantum Electronics•Aug 31, 1980•0 citations

Collisional effects in gas lasers

Ashish Agarwal, Rupamanjari Ghosh

The effects of phase-interrupting and velocity-changing collisions between active and perturber atoms on the spectral profile of a gas laser are studied. Exact analytical results for the density matrix are presented for the case of strong collisions in a unidirectional ring laser, and the laser intensity is then evaluated in the Doppler limit under the condition of self-consistency. The washout of the hole burning in the steady-state population difference and the broadening of the laser line shape are discussed. The results of the third-order perturbation theory are compared with the exact calculations valid for an arbitrarily intense pump.

Physical Review A•Feb 1, 1993•2 citations

Effects of Atomic Degeneracy and Cavity Anisotropy on the Behavior of a Gas Laser

Walter M. Doyle, Matthew B. White

Expressions are developed in this paper which describe the behavior of a gas laser having generalized polarization characteristics. It is found that degeneracies of the atomic energy levels play an important part in determining the behavior of such a laser since significant terms occur in the nonlinear polarization which are attributable to an oscillatory mixing of these levels. As a result, it is found, for example, that for single-mode operation the field intensity is greatest for either plane or circular polarization depending upon whether a $\ensuremath{\Delta}j=\ifmmode\pm\else\textpm\fi{}1$ or $\ensuremath{\Delta}j=0$ atomic transition is involved in the laser action. For two-mode operation, on the other hand, the behavior depends in a complicated way both on the polarization states of the oscillations and on the degree of degeneracy of the energy levels. This behavior is discussed in a number of special cases.

Physical Review•Jul 8, 1966•47 citations

On the theory of polarization effects in gas lasers

Daan Lenstra

Abstract Starting from a theory in which laser operation is described as the excitation of the natural modes of an open-resonator system, the case of a Fabry-Perot resonator with plane-parallel mirrors is treated. It is shown that, in the case of weakly anisotropic mirrors, the natural modes can be grouped in pairs, such that each pair corresponds to one scalar longitudinal mode. In that case, laser operation can and will be described in terms of these longitudinal modes, which then possess a vectorial field amplitude, in agreement with the usual formalism. The polarization preference in a single-mode gas laser operating on a transition between a singlet and a triplet state is investigated, taking into account differences in the relaxation constants for the various expectation values of atomic variables. A calculation of the effect on the relaxation constants due to interatomic collisions leads to the conclusion that theory and experiment are in good agreement with each other. Equations describing the time evolution of the polarization parameters of both modes in a two-mode operating gas laser are derived. It is found as a general rule that mode-mode interaction results in modes whose polarizations are mutually orthogonal. An exception to this rule is found in the case in which the single-mode preference is for circular polarization. The influence of two specific mirror anisotropies is discussed. The polarization behaviour of a single-mode gas laser in the presence of (partly) applied, transverse magnetic fields is extensively dealt with. It appears to be essential to distinguish between the case in which the magnetic field is applied only to a fraction of the active medium and the case in which the magnetic field is uniform in the entire medium. This distinction is shown to lead to a satisfactory theoretical description of a certain class of experiments. In the case of two other experiments, good agreement with the theory is obtained, by assuming the presence of mirror anisotropies of acceptable kind and size. Finally, the influence of small anisotropies on the degree of polarization of a single-mode gas laser is theoretically investigated, when the latter is polarized by means of a strong transverse magnetic field.

•Feb 1, 1979•0 citations

Limits of stability of two-mode emission in a strong field

I. V. Evseev, V. M. Ermachenko

A theoretical analysis is made of the two-mode emission from a gas laser in the vicinity of the symmetric position of the modes relative to the center of the gain profile when the intensities of the modes in the symmetric position cannot be regarded as low. The example of a homogeneously broadened spectral line is used in an investigation of the range of stable two-mode emission as a function of the relative excitation of the medium.

Soviet Journal of Quantum Electronics•Jul 31, 1976•1 citation
A theoretical analysis is made of the stability range of stimulated emission of two modes with orthogonal and parallel polarizations. The case of transitions between active levels of momenta ja = jb = 1 in a relatively strongly excited medium is considered. It is found that, in contrast to the case of parallel polarizations, emission of two modes with orthogonal polarizations is possible even when the mode spacing is small. Investigation is made of the influence of the quadrupole polarization of the medium on the width of the two-mode emission range. It is shown that the results obtained by calculating the polarization of the medium to within terms cubic in respect of the field amplitude describe correctly relatively highly excited active media.
A theoretical investigation is made of the feasibility of simultaneous laser action due to adjacent transitions in atoms of a gaseous medium with level momenta j/sub b/..-->..j/sub c/ and j/sub b/..-->..j/sub a/. In the case of small relative excesses of the population inversions of the active levels over the threshold, an expression is derived for the region of simultaneous laser action with parallel and orthogonally polarized fields. The limiting cases of homogeneously and inhomogeneously broadened lines are studied. Calculations are made allowing for depolarizing atomic collisions. For a homogeneously broadened line and negligible degeneracy of the levels, a region of simultaneous laser action is found for an arbitrary relative excess of the population inversion over the threshold.
The effects of phase-interrupting and velocity-changing collisions between active and perturber atoms on the spectral profile of a gas laser are studied. Exact analytical results for the density matrix are presented for the case of strong collisions in a unidirectional ring laser, and the laser intensity is then evaluated in the Doppler limit under the condition of self-consistency. The washout of the hole burning in the steady-state population difference and the broadening of the laser line shape are discussed. The results of the third-order perturbation theory are compared with the exact calculations valid for an arbitrarily intense pump.
Expressions are developed in this paper which describe the behavior of a gas laser having generalized polarization characteristics. It is found that degeneracies of the atomic energy levels play an important part in determining the behavior of such a laser since significant terms occur in the nonlinear polarization which are attributable to an oscillatory mixing of these levels. As a result, it is found, for example, that for single-mode operation the field intensity is greatest for either plane or circular polarization depending upon whether a $\ensuremath{\Delta}j=\ifmmode\pm\else\textpm\fi{}1$ or $\ensuremath{\Delta}j=0$ atomic transition is involved in the laser action. For two-mode operation, on the other hand, the behavior depends in a complicated way both on the polarization states of the oscillations and on the degree of degeneracy of the energy levels. This behavior is discussed in a number of special cases.
Abstract Starting from a theory in which laser operation is described as the excitation of the natural modes of an open-resonator system, the case of a Fabry-Perot resonator with plane-parallel mirrors is treated. It is shown that, in the case of weakly anisotropic mirrors, the natural modes can be grouped in pairs, such that each pair corresponds to one scalar longitudinal mode. In that case, laser operation can and will be described in terms of these longitudinal modes, which then possess a vectorial field amplitude, in agreement with the usual formalism. The polarization preference in a single-mode gas laser operating on a transition between a singlet and a triplet state is investigated, taking into account differences in the relaxation constants for the various expectation values of atomic variables. A calculation of the effect on the relaxation constants due to interatomic collisions leads to the conclusion that theory and experiment are in good agreement with each other. Equations describing the time evolution of the polarization parameters of both modes in a two-mode operating gas laser are derived. It is found as a general rule that mode-mode interaction results in modes whose polarizations are mutually orthogonal. An exception to this rule is found in the case in which the single-mode preference is for circular polarization. The influence of two specific mirror anisotropies is discussed. The polarization behaviour of a single-mode gas laser in the presence of (partly) applied, transverse magnetic fields is extensively dealt with. It appears to be essential to distinguish between the case in which the magnetic field is applied only to a fraction of the active medium and the case in which the magnetic field is uniform in the entire medium. This distinction is shown to lead to a satisfactory theoretical description of a certain class of experiments. In the case of two other experiments, good agreement with the theory is obtained, by assuming the presence of mirror anisotropies of acceptable kind and size. Finally, the influence of small anisotropies on the degree of polarization of a single-mode gas laser is theoretically investigated, when the latter is polarized by means of a strong transverse magnetic field.