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

Journal of Physics B Atomic and Molecular Physics

Zero-field level crossing of the 633 nm Ne line in resonance absorption

Birger Stahlberg, Markus Lindberg, Peter Jungner

Published Feb 28, 1985• 18 citations
Publisher

Abstract

The authors have investigated the zero-field level crossing lineshape in resonance absorption. A single-mode HeNe laser beam at 633 nm is applied to an external neon-gas absorption cell in a longitudinal magnetic field. They compare the measured lineshapes with theoretical predictions. Two superposed nonlinear Lorentzian-shaped resonances, known as the population effect of the 2p 4 -3s 2 transition and the Zeeman coherence effect of the lower 2p 4 level, appear on the background caused by the inhomogeneous broadening. Taking into account the background and the power broadening the authors obtain the linewidths at zero pressure gamma (2p 4 ,3s 2 )=(7.7+or-2.1) MHz and gamma (2p 4 )=(8.4+or-1.2) MHz. For the neon pressure broadening the authors get for pressures below 200 Pa (1.5 Torr) d gamma (2p 4 ,3s 2 )/dp=0.20+or-0.02 MHz Pa -1 and d(2p 4 )/dp=0.040+or-0.007 MHz Pa -1 . Their values are in acceptable agreement with the values obtained with other spectroscopic methods.

DOI
10.1088/0022-3700/18/4/010

Related papers

Polarisation properties of the stimulated zero-field level crossing

Peter Jungner, Birger Stahlberg, Markus Lindberg

The polarisation properties of the single mode linearly polarised laser beam interaction with a Doppler broadened absorber has been investigated. The absorber is placed in a longitudinal tunable magnetic field. The laser beam is analysed with a polariser after it has traversed the absorber. With various analyser rotation angles the lineshapes of the nonlinear resonances known as the population effect and the Zeeman coherence effect have been studied near zero magnetic field tuning. Theoretical predictions derived from the semi-classical laser theory are compared with experimental results. The experiment has been carried out with a low power thermally stabilised 633 nm He-He laser. The measured lineshapes of the resonances of the 2 p 4 -3 s 2 transition in neon agree well with the theoretical predictions. By using an analyser in the beam an improved signal-to-noise ratio is shown to result.

Physica Scripta•Oct 1, 1988•5 citations

Resonance broadening in neon at low densities

P. E. G. Baird, Keith R. Burnett, Roland M. Damaschini +2 more

The spectral profile of the strongly resonance-broadened transition lambda 585.2 nm of Ne I has been studied in absorption. A narrow-band tunable dye laser probed a weak discharge in natural neon cooled with liquid nitrogen. The Lorentzian width extrapolated to zero density was found to be 108+or-20 MHz, consistent with the value 114+or-4 MHz calculated from the natural widths of the levels. There is no indication of the excess width found in earlier emission experiments in helium and neon. A preliminary result of (1.7+or-0.2)10 -21 MHz atom -1 m 3 was obtained for the broadening constant of lambda 585.2 nm in absorption at 77K. This is consistent with the value found in emission.

Journal of Physics B Atomic and Molecular Physics•Mar 14, 1979•11 citations

Narrow high-order magnetooptic resonances in neon utilizing the 3s2–2p4transition

Э. Г. Сапрыкин, V P Soldatov, V. A. Sorokin

Under conditions of interaction between a high-intensity traveling laser wave and the 3s2–2p4 neon transition, a narrow component due to saturation of high-order absorption was recorded in a difference magnetooptic resonance. This component was due to field-induced coherence between magnetic sublevels with the quantum numbers ±2 of the 2p4 level (hexadecapole moment) and was used to determine the relaxation constant Γ4n. The collisional broadening ∂Γ4n/∂p determined as a result of a mathematical analysis of the magnetic spectrograms was 3 ± 0.3 MHz/Torr. The collisional broadening of the alignment relaxation constant of the 2p4 level measured under the same conditions was 4 ± 0.2 MHz/Torr.

Soviet Journal of Quantum Electronics•Oct 31, 1986•0 citations

Population trapping in the neon 2p3to 1s4transition

Russell McLean, R. J. Ballagh, D. M. Warrington

The fluorescence observed when a single-mode laser drives the 2p 3 (J=0) to 1s 4 (J=1) neon transition displays a narrow minimum as an applied magnetic field is varied. A detailed theoretical analysis of the system confirms that this resonance is due to the formation of a Zeeman coherence in the lower level which traps the population there. The dominant contribution to the population trapping comes from the atomic velocity classes for which the atom-laser detuning is close to zero, and for the case of exact resonance analytic expressions are obtained for dip width and depth. A broad minimum which also appears in the profile is shown to originate from incoherent processes in the atomic ensemble.

Journal of Physics B Atomic and Molecular Physics•Jun 28, 1985•24 citations

Experimental investigation of hidden alignment in Ne plasma using linear laser magneto-optical spectroscopy

V.A. Polischuk, Emilia A. Alipieva

Summary form only given, as follows. We investigated the hidden alignment of Ne plasma in a magnetic field observing the optical characteristics of the medium-absorption and refraction. A tunable single frequency laser beam was used as a probe beam. Depending on the direction of the applied magnetic field and the geometry of observation, the dependence of the plasma birefringence or dichroism on the magnetic field was registered. The dye laser was tuned to /spl lambda/=607.4 nm (2p/sub 3/-1s/sub 4/ Ne transition). The dependence on the external magnetic field of the laser beam intensity passed through the Ne discharge cell was registered, for various laser frequencies in the limits of the absorption line. At the edge of the absorption line, the signal of the dichroism consists of two Lorentzian components while at the center of the absorption line the wide component is absent. The wide component width depends on neon pressure as: H(P)=(1.64/spl plusmn/0.03) gauss + P(torr) (0.33/spl plusmn/0.08) gauss/torr. This value is in a good agreement with other results concerning the lifetime of the 1s/sub 4/ state. The mechanism of alignment formation in this state is not clear. This state could not be aligned by light absorption following a quantitative calculation. The irradiation of atoms is isotropic within the limits of all the absorption line because of the high magnitude of absorption for the 1s/sub 4/-1s/sub 0/ transition. We consider the optical pumping as the most probable mechanism for alignment of this state. The magnitude of absorption on the s-p neon transitions are not high. The intensity of the spontaneous emission beam along the tube is greater than in the perpendicular direction. If the quantization axis coincides with the tube axis, this beam empties the magnetic sublevels with M=/spl plusmn/1, thus creating longitudinal alignment. The absence of a signal at the center of the absorption line can be explained by the high selfabsorption on the s-p transitions. The width of the narrow component of the signal is approximately 0.7 gauss. Its pressure dependence is small. We have established experimentally the absence of signals of such width in the spontaneous emission from 2p levels. Hence, all optical mechanisms of alignment transmission from higher or from lower states to the 1s/sub 4/ state are excluded. Apparently this signal arises from alignment of metastable state 1s/sub 5/. In our opinion the collisions are the most probable mechanism of alignment transmission.

Trans Black Sea Region Symposium on Applied Electromagnetism•Nov 11, 2002•0 citations

Nonlinear Level Crossing in the Standing-Wave Field

Kōichi Shimoda

The nonlinear susceptibility of a gas of molecules under level crossing in a single-mode laser field is calculated by an iteration procedure. The higher-order solutions up to the fourth order are explicitly given for arbitrary number of nearly degenerate levels. Contributions of the second-, third-, and fourth-order terms are discussed with particular emphasis on the third-order term. The third-order solution reveals the level-crossing effect in saturated absorption with the half-width almost twice as broad as the Lamb clip when the decay rates of the upper and the lower states are different to some extent. Finally the zero-field level-crossing experiment of methane at 3.39 µm by Luntz et al. is reexamined to result in the pressure broadening of its half-width to be 7.4 MHz/Torr.

Japanese Journal of Applied Physics•Apr 1, 1972•9 citations
The authors have investigated the zero-field level crossing lineshape in resonance absorption. A single-mode HeNe laser beam at 633 nm is applied to an external neon-gas absorption cell in a longitudinal magnetic field. They compare the measured lineshapes with theoretical predictions. Two superposed nonlinear Lorentzian-shaped resonances, known as the population effect of the 2p 4 -3s 2 transition and the Zeeman coherence effect of the lower 2p 4 level, appear on the background caused by the inhomogeneous broadening. Taking into account the background and the power broadening the authors obtain the linewidths at zero pressure gamma (2p 4 ,3s 2 )=(7.7+or-2.1) MHz and gamma (2p 4 )=(8.4+or-1.2) MHz. For the neon pressure broadening the authors get for pressures below 200 Pa (1.5 Torr) d gamma (2p 4 ,3s 2 )/dp=0.20+or-0.02 MHz Pa -1 and d(2p 4 )/dp=0.040+or-0.007 MHz Pa -1 . Their values are in acceptable agreement with the values obtained with other spectroscopic methods.
The polarisation properties of the single mode linearly polarised laser beam interaction with a Doppler broadened absorber has been investigated. The absorber is placed in a longitudinal tunable magnetic field. The laser beam is analysed with a polariser after it has traversed the absorber. With various analyser rotation angles the lineshapes of the nonlinear resonances known as the population effect and the Zeeman coherence effect have been studied near zero magnetic field tuning. Theoretical predictions derived from the semi-classical laser theory are compared with experimental results. The experiment has been carried out with a low power thermally stabilised 633 nm He-He laser. The measured lineshapes of the resonances of the 2 p 4 -3 s 2 transition in neon agree well with the theoretical predictions. By using an analyser in the beam an improved signal-to-noise ratio is shown to result.
The spectral profile of the strongly resonance-broadened transition lambda 585.2 nm of Ne I has been studied in absorption. A narrow-band tunable dye laser probed a weak discharge in natural neon cooled with liquid nitrogen. The Lorentzian width extrapolated to zero density was found to be 108+or-20 MHz, consistent with the value 114+or-4 MHz calculated from the natural widths of the levels. There is no indication of the excess width found in earlier emission experiments in helium and neon. A preliminary result of (1.7+or-0.2)10 -21 MHz atom -1 m 3 was obtained for the broadening constant of lambda 585.2 nm in absorption at 77K. This is consistent with the value found in emission.
Under conditions of interaction between a high-intensity traveling laser wave and the 3s2–2p4 neon transition, a narrow component due to saturation of high-order absorption was recorded in a difference magnetooptic resonance. This component was due to field-induced coherence between magnetic sublevels with the quantum numbers ±2 of the 2p4 level (hexadecapole moment) and was used to determine the relaxation constant Γ4n. The collisional broadening ∂Γ4n/∂p determined as a result of a mathematical analysis of the magnetic spectrograms was 3 ± 0.3 MHz/Torr. The collisional broadening of the alignment relaxation constant of the 2p4 level measured under the same conditions was 4 ± 0.2 MHz/Torr.
The fluorescence observed when a single-mode laser drives the 2p 3 (J=0) to 1s 4 (J=1) neon transition displays a narrow minimum as an applied magnetic field is varied. A detailed theoretical analysis of the system confirms that this resonance is due to the formation of a Zeeman coherence in the lower level which traps the population there. The dominant contribution to the population trapping comes from the atomic velocity classes for which the atom-laser detuning is close to zero, and for the case of exact resonance analytic expressions are obtained for dip width and depth. A broad minimum which also appears in the profile is shown to originate from incoherent processes in the atomic ensemble.
Summary form only given, as follows. We investigated the hidden alignment of Ne plasma in a magnetic field observing the optical characteristics of the medium-absorption and refraction. A tunable single frequency laser beam was used as a probe beam. Depending on the direction of the applied magnetic field and the geometry of observation, the dependence of the plasma birefringence or dichroism on the magnetic field was registered. The dye laser was tuned to /spl lambda/=607.4 nm (2p/sub 3/-1s/sub 4/ Ne transition). The dependence on the external magnetic field of the laser beam intensity passed through the Ne discharge cell was registered, for various laser frequencies in the limits of the absorption line. At the edge of the absorption line, the signal of the dichroism consists of two Lorentzian components while at the center of the absorption line the wide component is absent. The wide component width depends on neon pressure as: H(P)=(1.64/spl plusmn/0.03) gauss + P(torr) (0.33/spl plusmn/0.08) gauss/torr. This value is in a good agreement with other results concerning the lifetime of the 1s/sub 4/ state. The mechanism of alignment formation in this state is not clear. This state could not be aligned by light absorption following a quantitative calculation. The irradiation of atoms is isotropic within the limits of all the absorption line because of the high magnitude of absorption for the 1s/sub 4/-1s/sub 0/ transition. We consider the optical pumping as the most probable mechanism for alignment of this state. The magnitude of absorption on the s-p neon transitions are not high. The intensity of the spontaneous emission beam along the tube is greater than in the perpendicular direction. If the quantization axis coincides with the tube axis, this beam empties the magnetic sublevels with M=/spl plusmn/1, thus creating longitudinal alignment. The absence of a signal at the center of the absorption line can be explained by the high selfabsorption on the s-p transitions. The width of the narrow component of the signal is approximately 0.7 gauss. Its pressure dependence is small. We have established experimentally the absence of signals of such width in the spontaneous emission from 2p levels. Hence, all optical mechanisms of alignment transmission from higher or from lower states to the 1s/sub 4/ state are excluded. Apparently this signal arises from alignment of metastable state 1s/sub 5/. In our opinion the collisions are the most probable mechanism of alignment transmission.
The nonlinear susceptibility of a gas of molecules under level crossing in a single-mode laser field is calculated by an iteration procedure. The higher-order solutions up to the fourth order are explicitly given for arbitrary number of nearly degenerate levels. Contributions of the second-, third-, and fourth-order terms are discussed with particular emphasis on the third-order term. The third-order solution reveals the level-crossing effect in saturated absorption with the half-width almost twice as broad as the Lamb clip when the decay rates of the upper and the lower states are different to some extent. Finally the zero-field level-crossing experiment of methane at 3.39 µm by Luntz et al. is reexamined to result in the pressure broadening of its half-width to be 7.4 MHz/Torr.