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

Physical Review A

Depolarization of optically pumped sodium atoms by wall surfaces

Masayoshi TANAKA, T. Ohshima, K. Katori, M̄. Fujiwara, Takahisa Itahashi, Hiroshi Ogata, Michiya KONDO

Published Feb 1, 1990• 24 citations
Publisher

Abstract

The polarizations of sodium atoms optically pumped by a single-mode cw ring dye laser were measured as a function of the pumping power, sodium-vapor thickness, and external magnetic field for Pyrex glass and copper walls with and without dry-film coating. Observed quantities were analyzed by a simple optical pumping model in which the effect of the radiation trapping was taken into account. Assuming that the depolarization of the sodium atom was mainly induced by the local magnetic field at the sodium atom during its adsorption on the wall surface, the calculations could successfully reproduce the observed polarizations.

DOI
10.1103/physreva.41.1496

Related papers

Optical Pumping of Dense Charge-Exchange Targets for Polarized Ion Sources

Wayne D. Cornelius, DAVID J. TAYLOR, R. L. York +1 more

Optical pumping by a single-frequency cw ring dye laser of thick sodium vapor targets ($\mathrm{NL}>{10}^{13}$ atoms/${\mathrm{cm}}^{2}$) without buffer gas has been investigated for application in a polarized ion source. The atomic polarization of the sodium was determined from the optical rotation of a second dye laser tuned midway between the $D$ lines. Rate-equation calculations reproduce the experimental data and predict very high polarizations ($P>~0.8$) with the use of one or more single-frequency dye lasers in thick alkali-metal vapor targets.

Physical Review Letters•Sep 20, 1982•38 citations

Interaction of spin-polarized atoms with a surface studied by optical-reflection spectroscopy

S. Grafström, Dieter Suter

We present an experiment for the investigation of the interaction of spin-polarized Na atoms with a dielectric surface. A laser beam, which is resonant with an atomic transition, probes the spin polarization near the surface. It is reflected at the surface and the change of its polarization is measured. Our analysis takes into account that the spin polarization is reduced near the surface because of surface-induced spin relaxation. The theory shows that strong wall relaxation leads to a clear modification of the shape and strength of the optical line. The dependence of the line shape on the angle of incidence immediately below the critical angle of total internal reflection provides a sensitive tool for the quantitative determination of the depolarization probability \ensuremath{\varepsilon} per wall collision. Measurements performed at a Pyrex glass surface provide a clear experimental confirmation of the theory and yield a value of \ensuremath{\varepsilon}\ensuremath{\approxeq}0.5. The case of weak wall relaxation is exemplified by experimental results from a silicone-coated glass surface, which are equally well reproduced by the theory. The method offers the prospect of using surface-induced spin relaxation for the study of surface properties and atom-surface interactions for various surfaces. \textcopyright{} 1996 The American Physical Society.

Physical Review A•Sep 1, 1996•17 citations

Polarization of an atomic sodium beam by laser optical pumping

Jack T. Cusma, L. W. Anderson

A highly polarized $^{23}\mathrm{Na}$ atomic beam is produced by optical pumping with the use of either a multimode cw dye laser or a single-mode ring dye laser followed by a double-passed acousto-optic modulator. Electron-spin polarizations of 0.72 to 0.90 are obtained.

Physical Review A•Aug 1, 1983•30 citations

Wall-collision effect on optically polarized atoms in small and hot vapor cells

Yue Chang, Jie Qin

In atomic vapor cells, atoms collide with the inner surface, causing their spin to randomize on the walls. This wall-depolarizing effect can be diffusive and it becomes more pronounced in smaller vapor cells under high temperatures. In this work we investigate the polarization of optically pumped alkali-metal atoms in a millimeter-sized cell heated to $150{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\text{C}$. We consider two extreme boundary conditions, fully depolarizing and nondepolarizing boundaries, and we provide an analytical estimation of the polarization difference between them. In the nondepolarizing case, the pump beam's absorption is proportional to the average atomic polarization. However, for fully depolarizing walls, the absorption peak may correspond to a polarization minimum. To mitigate the wall effect, we propose reducing the pump beam's diameter while maintaining the pump power to prevent illumination of the cell wall and increase the pump intensity in the central area. This is crucial for compact vapor-cell devices where the laser frequency cannot be detuned since it is locked to the absorption peaks. Additionally, we analyze the wall-depolarizing effect on the performance of an alkali-metal atomic magnetometer operating in the spin-exchange relaxation-free regime. We show that the signal strength is highly limited by wall collisions and we provide an upper bound for it.

arXiv:2305.11500•Physical Review A•Feb 16, 2024•7 citations

Relaxation of electron polarization for optically pumped rubidium atoms

W. Nagengast, A. Nass, C. Großhauser +2 more

Relaxation time constants of electron polarization, 〈Sz〉, for optically pumped rubidium atoms in a drifilm coated glass cell have been investigated with the Faraday rotation method. The dependence of the 〈Sz〉 relaxation time on pump cell temperature, rubidium density and applied magnetic field has been determined with high precision. The measurements allow the determination of the local magnetic field on the surface, alkali-wall binding energy and wall-dwell time. Furthermore, the change of relaxation time caused by admixtures of molecular hydrogen, nitrogen and oxygen has been investigated. No influence due to the addition of hydrogen could be detected up to a density of 3.3×1014 cm−3 at typical rubidium densities of several 1011 cm−3. The cross section for depolarizing collisons with molecular oxygen has been determined to be 7.50×10−15 cm2. The corresponding cross section for nitrogen was found to be two orders of magnitude lower. The experimental results are discussed in respect to the performance of spin exchange sources for nuclear polarized hydrogen and deuterium.

Journal of Applied Physics•Jun 1, 1998•6 citations

Optical-pumping-induced ring structures of polarized laser light propagating through sodium vapor

B. Röhricht, U. Rusch, S. Dangel +4 more

We describe a sensitive technique for observing small transverse modifications to intensity, phase, and polarization arising in nonlinear propagation of a laser beam through an atomic vapor. The technique, which in essence is an interferometric one, is based on the use of crossed polarizers that are nearly but not exactly pure circular. Illustrative results are presented for cw dye-laser radiation propagating through collisionally broadened atomic sodium that is near resonant to the D1 line. Well-defined ring patterns produced by nonlinear interactions are observed at both positive and negative laser detunings.

Journal of the Optical Society of America B•Aug 1, 1995•3 citations
The polarizations of sodium atoms optically pumped by a single-mode cw ring dye laser were measured as a function of the pumping power, sodium-vapor thickness, and external magnetic field for Pyrex glass and copper walls with and without dry-film coating. Observed quantities were analyzed by a simple optical pumping model in which the effect of the radiation trapping was taken into account. Assuming that the depolarization of the sodium atom was mainly induced by the local magnetic field at the sodium atom during its adsorption on the wall surface, the calculations could successfully reproduce the observed polarizations.
Optical pumping by a single-frequency cw ring dye laser of thick sodium vapor targets (NL>1013\mathrm{NL}>{10}^{13}NL>1013 atoms/cm2{\mathrm{cm}}^{2}cm2) without buffer gas has been investigated for application in a polarized ion source. The atomic polarization of the sodium was determined from the optical rotation of a second dye laser tuned midway between the DDD lines. Rate-equation calculations reproduce the experimental data and predict very high polarizations (P> 0.8P>~0.8P> 0.8) with the use of one or more single-frequency dye lasers in thick alkali-metal vapor targets.
We present an experiment for the investigation of the interaction of spin-polarized Na atoms with a dielectric surface. A laser beam, which is resonant with an atomic transition, probes the spin polarization near the surface. It is reflected at the surface and the change of its polarization is measured. Our analysis takes into account that the spin polarization is reduced near the surface because of surface-induced spin relaxation. The theory shows that strong wall relaxation leads to a clear modification of the shape and strength of the optical line. The dependence of the line shape on the angle of incidence immediately below the critical angle of total internal reflection provides a sensitive tool for the quantitative determination of the depolarization probability \ensuremath{\varepsilon} per wall collision. Measurements performed at a Pyrex glass surface provide a clear experimental confirmation of the theory and yield a value of \ensuremath{\varepsilon}\ensuremath{\approxeq}0.5. The case of weak wall relaxation is exemplified by experimental results from a silicone-coated glass surface, which are equally well reproduced by the theory. The method offers the prospect of using surface-induced spin relaxation for the study of surface properties and atom-surface interactions for various surfaces. \textcopyright{} 1996 The American Physical Society.
A highly polarized 23Na^{23}\mathrm{Na}23Na atomic beam is produced by optical pumping with the use of either a multimode cw dye laser or a single-mode ring dye laser followed by a double-passed acousto-optic modulator. Electron-spin polarizations of 0.72 to 0.90 are obtained.
In atomic vapor cells, atoms collide with the inner surface, causing their spin to randomize on the walls. This wall-depolarizing effect can be diffusive and it becomes more pronounced in smaller vapor cells under high temperatures. In this work we investigate the polarization of optically pumped alkali-metal atoms in a millimeter-sized cell heated to $150{\phantom{\rule{0.16em}{0ex}}}^{\ensuremath{\circ}}\text{C}$. We consider two extreme boundary conditions, fully depolarizing and nondepolarizing boundaries, and we provide an analytical estimation of the polarization difference between them. In the nondepolarizing case, the pump beam's absorption is proportional to the average atomic polarization. However, for fully depolarizing walls, the absorption peak may correspond to a polarization minimum. To mitigate the wall effect, we propose reducing the pump beam's diameter while maintaining the pump power to prevent illumination of the cell wall and increase the pump intensity in the central area. This is crucial for compact vapor-cell devices where the laser frequency cannot be detuned since it is locked to the absorption peaks. Additionally, we analyze the wall-depolarizing effect on the performance of an alkali-metal atomic magnetometer operating in the spin-exchange relaxation-free regime. We show that the signal strength is highly limited by wall collisions and we provide an upper bound for it.
Relaxation time constants of electron polarization, 〈Sz〉, for optically pumped rubidium atoms in a drifilm coated glass cell have been investigated with the Faraday rotation method. The dependence of the 〈Sz〉 relaxation time on pump cell temperature, rubidium density and applied magnetic field has been determined with high precision. The measurements allow the determination of the local magnetic field on the surface, alkali-wall binding energy and wall-dwell time. Furthermore, the change of relaxation time caused by admixtures of molecular hydrogen, nitrogen and oxygen has been investigated. No influence due to the addition of hydrogen could be detected up to a density of 3.3×1014 cm−3 at typical rubidium densities of several 1011 cm−3. The cross section for depolarizing collisons with molecular oxygen has been determined to be 7.50×10−15 cm2. The corresponding cross section for nitrogen was found to be two orders of magnitude lower. The experimental results are discussed in respect to the performance of spin exchange sources for nuclear polarized hydrogen and deuterium.
We describe a sensitive technique for observing small transverse modifications to intensity, phase, and polarization arising in nonlinear propagation of a laser beam through an atomic vapor. The technique, which in essence is an interferometric one, is based on the use of crossed polarizers that are nearly but not exactly pure circular. Illustrative results are presented for cw dye-laser radiation propagating through collisionally broadened atomic sodium that is near resonant to the D1 line. Well-defined ring patterns produced by nonlinear interactions are observed at both positive and negative laser detunings.