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

Gas laser with a phase anisotropy in an axial magnetic field for arbitrary relative excitation of the active medium

А. Ч. Измайлов

Published Nov 30, 1982• 0 citations
Publisher

Abstract

A theoretical analysis is made of the characteristics of a single- and two-mode gas laser with an anisotropic resonator in an axial magnetostatic field with arbitrary relative excitation of the active medium for an atomic transition with total level momenta of 0 and 1. Using an example of a homogeneously broadened spectral line, it is shown that the results of calculations made to within terms cubic with respect to the electric field give a correct qualitative description of the characteristics of two-mode lasing.

DOI
10.1070/qe1982v012n11abeh006088

Related papers

Polarization Properties of a Single-Mode Operating Gas Laser in a Small Axial Magnetic Field

W. van Haeringen

The polarization properties of a single-mode operating gas laser in a small axial magnetic field (field splitting\ensuremath{\ll}natural linewidth) with an initial cavity anisotropy are considered in detail. Expressions are given for the effects on the polarization parameters due to the active medium, the external field, and the initial anisotropy of the cavity. The cooperation of these three effects is discussed. Existing theories are in this respect shown to be either incomplete or inadequate. Specializations are made to several types of atomic transitions and cavity anisotropies. A group of low-field polarization phenomena observed on the He-Ne 1.153-\ensuremath{\mu} mode is theoretically discussed. In particular, it is shown that the observed polarization flip by tuning through the line center and the hysteresis effect, observed by Kannelaud and Culshaw, can be completely understood assuming a cavity whose main anisotropy is a linear phase anisotropy. At zero or very small magnetic field the theory predicts a preference for linear or circular polarization, depending on the type of atomic transition.

Physical Review•Jun 10, 1967•109 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

Magnetic field and pressure effects in a saturated gas laser amplifier

Robert T. Menzies

Theoretical and experimental studies of a gas laser amplifier are presented, assuming the amplifier is operating with a saturating optical frequency signal. The analysis is primarily concerned with the effects of the gas pressure and the presence of an axial magnetic field on the characteristics of the amplifying medium. Semiclassical radiation theory is used, along with a density matrix description of the atomic medium which relates the motion of single atoms to the macroscopic observables. A two-level description of the atom, using phenomenological source rates and decay rates, forms the basis of our analysis of the gas laser medium. Pressure effects are taken into account to a large extent through suitable choices of decay rate parameters. Two methods for calculating the induced polarization of the atomic medium are used. The first method utilizes a perturbation expansion which is valid for signal intensities which barely reach saturation strength, and it is quite general in applicability. The second method is valid for arbitrarily strong signals, but it yields tractable solutions only for zero magnetic field or for axial magnetic fields large enough such that the Zeeman splitting is much larger than the power broadened homogeneous linewidth of the laser transition. The effects of pressure broadening of the homogeneous spectral linewidth are included in both the weak-signal and strong-signal theories; however the effects of Zeeman sublevel-mixing collisions are taken into account only in the weak-signal theory. The behavior of a He-Ne gas laser amplifier in the presence of an axial magnetic field has been studied experimentally by measuring gain and Faraday rotation of linearly polarized resonant laser signals for various values of input signal intensity, and by measuring nonlinearity - induced anisotropy for elliptically polarized resonant laser signals of various input intensities. Two high-gain transitions in the 3.39-μ region were used for study: a J = 1 to J = 2 (3s2 → 3p4) transition and a J = 1 to J = 1 (3s2 → 3p2) transition. The input signals were tuned to the centers of their respective resonant gain lines. The experimental results agree quite well with corresponding theoretical expressions which have been developed to include the nonlinear effects of saturation strength signals. The experimental results clearly show saturation of Faraday rotation, and for the J = 1 t o J = 1 transition a Faraday rotation reversal and a traveling wave gain dip are seen for small values of axial magnetic field. The nonlinearity induced anisotropy shows a marked dependence on the gas pressure in the amplifier tube for the J = 1 to J = 2 transition; this dependence agrees with the predictions of the general perturbational or weak signal theory when allowances are made for the effects of Zeeman sublevel-mixing collisions. The results provide a method for measuring the upper (neon 3s2) level quadrupole moment decay rate, the dipole moment decay rates for the 3s2 → 3p4 and 3s2 → 3p2 transitions, and the effects of various types of collision processes on these decay rates.

•Aug 12, 2015•1 citation

Change in the parameters of a light wave during propagation through a resonant gaseous medium in a magnetic field

А. Ч. Измайлов

A theoretical analysis is made of the resonant interaction between a traveling monochromatic light wave of arbitrary intensity and polarization and the 1/21/2 and 10 transitions in gas atoms in a magnetic field. An analysis is made of the influence of atomic collisions and coherence of the Zeeman sublevels of the terms on the structure of nonlinear magnetooptic resonances in the amplitude and polarization characteristics of the wave. Some features of nonlinear magnetooptic resonances for laser excitation of atoms from the ground state are noted. A study is made of the Faraday rotation and self-rotation of the polarization ellipse of the radiation as a function of the detuning of the wave frequency, the saturation parameter, and the optical density of the gas. The stability of the polarization of light in the medium is discussed. It is noted that these laws may be used to analyze and control the radiation characteristics of lasers and amplifiers when the level of saturation of a resonant gaseous medium in a magnetic field is high.

Soviet Journal of Quantum Electronics•Mar 31, 1988•2 citations

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
A theoretical analysis is made of the characteristics of a single- and two-mode gas laser with an anisotropic resonator in an axial magnetostatic field with arbitrary relative excitation of the active medium for an atomic transition with total level momenta of 0 and 1. Using an example of a homogeneously broadened spectral line, it is shown that the results of calculations made to within terms cubic with respect to the electric field give a correct qualitative description of the characteristics of two-mode lasing.
The polarization properties of a single-mode operating gas laser in a small axial magnetic field (field splitting\ensuremath{\ll}natural linewidth) with an initial cavity anisotropy are considered in detail. Expressions are given for the effects on the polarization parameters due to the active medium, the external field, and the initial anisotropy of the cavity. The cooperation of these three effects is discussed. Existing theories are in this respect shown to be either incomplete or inadequate. Specializations are made to several types of atomic transitions and cavity anisotropies. A group of low-field polarization phenomena observed on the He-Ne 1.153-\ensuremath{\mu} mode is theoretically discussed. In particular, it is shown that the observed polarization flip by tuning through the line center and the hysteresis effect, observed by Kannelaud and Culshaw, can be completely understood assuming a cavity whose main anisotropy is a linear phase anisotropy. At zero or very small magnetic field the theory predicts a preference for linear or circular polarization, depending on the type of atomic transition.
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.
Theoretical and experimental studies of a gas laser amplifier are presented, assuming the amplifier is operating with a saturating optical frequency signal. The analysis is primarily concerned with the effects of the gas pressure and the presence of an axial magnetic field on the characteristics of the amplifying medium. Semiclassical radiation theory is used, along with a density matrix description of the atomic medium which relates the motion of single atoms to the macroscopic observables. A two-level description of the atom, using phenomenological source rates and decay rates, forms the basis of our analysis of the gas laser medium. Pressure effects are taken into account to a large extent through suitable choices of decay rate parameters. Two methods for calculating the induced polarization of the atomic medium are used. The first method utilizes a perturbation expansion which is valid for signal intensities which barely reach saturation strength, and it is quite general in applicability. The second method is valid for arbitrarily strong signals, but it yields tractable solutions only for zero magnetic field or for axial magnetic fields large enough such that the Zeeman splitting is much larger than the power broadened homogeneous linewidth of the laser transition. The effects of pressure broadening of the homogeneous spectral linewidth are included in both the weak-signal and strong-signal theories; however the effects of Zeeman sublevel-mixing collisions are taken into account only in the weak-signal theory. The behavior of a He-Ne gas laser amplifier in the presence of an axial magnetic field has been studied experimentally by measuring gain and Faraday rotation of linearly polarized resonant laser signals for various values of input signal intensity, and by measuring nonlinearity - induced anisotropy for elliptically polarized resonant laser signals of various input intensities. Two high-gain transitions in the 3.39-μ region were used for study: a J = 1 to J = 2 (3s2 → 3p4) transition and a J = 1 to J = 1 (3s2 → 3p2) transition. The input signals were tuned to the centers of their respective resonant gain lines. The experimental results agree quite well with corresponding theoretical expressions which have been developed to include the nonlinear effects of saturation strength signals. The experimental results clearly show saturation of Faraday rotation, and for the J = 1 t o J = 1 transition a Faraday rotation reversal and a traveling wave gain dip are seen for small values of axial magnetic field. The nonlinearity induced anisotropy shows a marked dependence on the gas pressure in the amplifier tube for the J = 1 to J = 2 transition; this dependence agrees with the predictions of the general perturbational or weak signal theory when allowances are made for the effects of Zeeman sublevel-mixing collisions. The results provide a method for measuring the upper (neon 3s2) level quadrupole moment decay rate, the dipole moment decay rates for the 3s2 → 3p4 and 3s2 → 3p2 transitions, and the effects of various types of collision processes on these decay rates.
A theoretical analysis is made of the resonant interaction between a traveling monochromatic light wave of arbitrary intensity and polarization and the 1/21/2 and 10 transitions in gas atoms in a magnetic field. An analysis is made of the influence of atomic collisions and coherence of the Zeeman sublevels of the terms on the structure of nonlinear magnetooptic resonances in the amplitude and polarization characteristics of the wave. Some features of nonlinear magnetooptic resonances for laser excitation of atoms from the ground state are noted. A study is made of the Faraday rotation and self-rotation of the polarization ellipse of the radiation as a function of the detuning of the wave frequency, the saturation parameter, and the optical density of the gas. The stability of the polarization of light in the medium is discussed. It is noted that these laws may be used to analyze and control the radiation characteristics of lasers and amplifiers when the level of saturation of a resonant gaseous medium in a magnetic field is high.
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.