Polarisation de la lumiere d'un laser He-Ne soumis a un champ magnetique

Dumont, Mario; Durand, G.

doi:10.1016/0031-9163(64)90727-9

Cited by 10 publications

(24 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A satisfactory description of certain experimental observations [22 J follows if the assumption is made that the applied transverse magnetic field was in fact inhomogeneous. In two other cases, i.e., [13,43], good agreement between theory and experiment is obtained by assuming the presence of cavity anisotropies of acceptable kind and size. Finally, the influence of small cavity anisotropies on the output of a single-mode gas laser, which is polarized by means of a transverse magnetic field, will be dealt with in some detail.…”

Section: Outline Of the Present Studymentioning

confidence: 85%

“…Although a comparison of these results with a set of experiments, viz. [13,22,42,43], seems at first sight to give qualitative agreement, a more detailed examination of the theoretical and the experimental results, especially in the transverse magnetic-field cases, brings several discrepancies to light [44,45].…”

Section: Short Review Of Literaturementioning

confidence: 90%

“…Our theory will be confronted with the earlier-mentioned set of experiments involving transverse magnetic fields, i.e., [13,22,43]. It will be shown that a magnetic field which is only partially applied to the laser medium leads to predictions of the polarization behaviour quite different from those concerning a field that is uniform in the entire active medium.…”

Section: Outline Of the Present Studymentioning

confidence: 99%

“…The quantum mechanical state of an atom will, as usual, be described by the density matrix aa P ba P ab P bb P (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) where p is a 3x3 matrix acting in the triplet state, p is a column 1 1 ba abt . vector, relating the upper and lower level; p = p is a row vector and p is a scalar, acting in the singlet state.…”

Section: S1 Derivation Of the Equations Of Motion Of Expectation Valuesmentioning

confidence: 99%

“…The field then couples to the electric-dipole operator ]j , which is given by [62] y = /2 p £ , (3)(4)(5)(6)(7)(8)(9)(10)(11)(12) where P =^<^>J^'> . (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13) and <¥" y ¥ > is the matrix element of \i between the states with wave 0' 3' 2 a b functions f^ and Y , respectively. The interaction hamiltonian is given by ^1 = -I'iL = -^V-£ , (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14) where…”

Section: S1 Derivation Of the Equations Of Motion Of Expectation Valuesmentioning

confidence: 99%

See 4 more Smart Citations

On the theory of polarization effects in gas lasers

Lenstra

1980

Physics Reports

View full text Add to dashboard Cite

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 investigated. 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 different relaxation constants for the density matrix. 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 polarizing 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 transverse magnetic field. CONTENTS

show abstract

Section: Outline Of the Present Studymentioning

confidence: 85%

Section: Short Review Of Literaturementioning

confidence: 90%

Section: Outline Of the Present Studymentioning

confidence: 99%

Section: S1 Derivation Of the Equations Of Motion Of Expectation Valuesmentioning

confidence: 99%

Section: S1 Derivation Of the Equations Of Motion Of Expectation Valuesmentioning

confidence: 99%

See 3 more Smart Citations

On the theory of polarization effects in gas lasers

Lenstra

1980

Physics Reports

View full text Add to dashboard Cite

show abstract

Polarization properties of a single-mode gas laser in transverse magnetic fields

Lenstra

1978

Appl. Phys.

View full text Add to dashboard Cite

Power characteristics of a helium-neon laser in a transverse magnetic field

Fridrikhov¹,

Terekhin²,

Lapshin³

et al. 1969

J Appl Spectrosc

View full text Add to dashboard Cite

Most of the numerous investigations of the effect of a magnetic field on the emission of a gas laser [1][2][3] relate to the case of an axial field. This is probably due to the fact that the magnetooptic effects in the two cases have several features in common [1] and the production of an extended transverse magnetic field presents some difficulty. Yet the transverse Zeeman effect in a gas laser is of definite interest. We know [2], for instance, that in a transverse magnetic field, laser emission continues to higher values of H than in an axial field. The presence of three Zeeman components in the emission leads to interesting polarization effects [3].Little attention has been given so far, however, to the investigation of the power characteristics in a transverse field, although this question is important both from the viewpoint of increasing the output power of a gas laser and, for instance, variation of the frequency of a laser by a magnetic field. These characteristics have not been considered at all in the case of laser emission on competing transitions.Finally, in most investigations the laser has beenexcited by a high-frequency field. The use of tubes excited by a glow discharge in a transverse magnetic field, i.e., the use of crossed electric and magnetic fields, can lead to specific plasma effects. An investigation of these effects will enable us to select the best operating conditions for a laser in a transverse magnetic field.The effect of a magnetic field on the power characteristics of a laser may be qualitatively different for lasers which differ in the factor by which the gain of the active medium exceeds the loss factor of the system. In view of this we used in our work several laser tubes with different output powers. They had a length l = 43-45 cm and were closed at the ends by quartz Brewster-angle windows. Tube No. 1, with internal diameter d = 3 mm, operated on an apparatus with a pumping system which allowed variation of the pressure and ratio of gases in the mixture. Tubes Nos. 2, Po, 3, and 4, with internal diameter d = 3.5 mm, had standard tel. units filling and different loss levels. The discharge was excited by adc supply. 80The transverse magnetic field was produced by electromagnets with pole pieces 30 and 35 cm long, which provided fields of up to H = 2000 Oe with a nonuniformity of not more 0 Fig. 1. Po = f(H): 1-4) A = 0.63t~; 1'-4') A= 3.39#; 1,1') I d = 35; 2,2') 50; 3, 3') 70; 4, 4') 90 mA. than 5% along the poles. The electromagnets could be powered from a stabilized direct voltage supply or from a VSA-11 pulsed voltage supply (pulse rate 50 Hz).The measurements were made with mirrors of two types -for the lines 0.63 p and 1.15 t~. In both cases we observed simultaneous emission on 3.39 t~. The length of the "piano-concave" resonator could be varied from 50 to 150 cm.The radiation receiver was an FI~U-28 photomultiplier for the 0.63 p and 1.15 g lines and a thermocouple for the

show abstract

Polarisation de la lumiere d'un laser He-Ne soumis a un champ magnetique

Cited by 10 publications

References 0 publications

On the theory of polarization effects in gas lasers

On the theory of polarization effects in gas lasers

Polarization properties of a single-mode gas laser in transverse magnetic fields

Power characteristics of a helium-neon laser in a transverse magnetic field

Contact Info

Product

Resources

About