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

The Review of Laser Engineering

Laser Cooling and Bose-Einstein Condensation. Atomic Beam Guide and Channeling toward Atom Lithography.

R. Ohmukai, Shinji Urabe, Masayoshi Watanabe

Published Jan 1, 2000• 0 citations
Publisher

Abstract

An atomic beam has been collimated, compressed, and deflected simultaneously by an atomic beam guide based on an tilted one-dimensional magneto-optical trap. Isotope-selected rubidium atoms were extracted from the naturally-mixed thermal atomic beam. We could extract more than 50% of the incident atoms as a deflection beam when we combined this deflection technique with the atomic deceleration using a broadband spectral light. We could manipulate the transverse displacement of the deflected beam precisely by modifying the quadrupole magnetic field. We also observed the well-collimated atomic beam to be channeled into the dipole force potential valleys formed by the standing wave light field.

DOI
10.2184/lsj.28.166

Related papers

Atomic beam guide by a one-dimensional magneto-optical trap

R. Ohmukai, S. Urabe, M. Watanbe

The fine control of a neutral atomic beam by radiation pressure has opened a new field called atom lithography. In particular, a direct writing method, which focuses an atomic beam with a standing-wave light field into narrow lines, has been demonstrated. A velocity-controlled and isotope-selected atomic beam is essential for improving the performance of this lithography method. An atomic deflection technique using radiation pressure is indispensable for producing such an atomic beam. Here we report on an atomic beam guide using a one-dimensional magneto-optical trap (1D-MOT). First we decelerate atoms whose velocities lie in the range between 250 and 320 m/s. A diode laser (780 nm) is used as the light source for deceleration and its injection current is modulated at 2 MHz. Then the decelerated beam is deflected by a tilted 1D-MOT, which consists of four copper rods and four rectangular mirrors.

Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR)•Jan 20, 2003•0 citations

Large angle guiding of atomic beams by magnetized video tape

H. Merimeche, Ralph Peter Bertram, D. Haubrich +4 more

Summary form only given. Laser cooling methods provide the possibility to obtain very well collimated and slow atomic beams. These intense sources have attracted new interest in the manipulation of atomic trajectories. Atom optical schemes based on the optical dipole force are very attractive, for example in atom lithography where atomic beams are focused by standing wave light fields, to create periodic nanostructures.

Conference on Lasers and Electro-Optics•Aug 29, 2005•0 citations

All-Optical Realization of an Atom Laser

Giovanni Cennini, Gunnar Ritt, Carsten Geckeler +1 more

We demonstrate an atom laser using all-optical techniques. A Bose-Einstein condensate of rubidium atoms is created by direct evaporative cooling in a quasistatic dipole trap realized with a single, tightly focused CO2-laser beam. An applied magnetic field gradient allows the formation of the condensate in a field-insensitive m(F)=0 spin projection only, which suppresses fluctuations of the chemical potential from stray magnetic fields. A collimated and monoenergetic beam of atoms is extracted from the Bose-Einstein condensate by continuously lowering the dipole trapping potential in a controlled way to form a novel type of atom laser.

arXiv:cond-mat/0307620•Physical Review Letters•Dec 12, 2003•86 citations

Optical collimation and compression of a thermal atomic beam

Chun-Cheng Tsao, Youjun Wang, J. Weiner +1 more

We have performed an experiment to optically cool and compress a thermal beam of sodium atoms by employing a two-dimensional version of a magneto-optical trap. The beam compressor employs a tapered transverse magnetic field gradient formed by four pairs of permanent magnets. We measure the efficiency of collimation and compression as function of longitudinal velocity group.

Journal of Applied Physics•Jul 1, 1996•21 citations

Shock wave loading of a magnetic guide

L. Kindt

The atom laser has long been a holy grail within atom physics and with the creation of an atom laser we hope to bring a similar revolution in to the field of atom optics. With the creation of the Bose-Einstein Condensate (BEC) in 1995 the path to an atom laser was initiated. An atom laser is continues source of BEC. In a Bose condensate all the atoms occupy the same quantum state and can be described by the same wave function and phase. With an atom laser the De Broglie wavelength of atoms can be much smaller than the wavelength of light. Due to the ultimate control over the atoms the atom laser is very interesting for atom optics, lithography, metrology, etching and deposition of atoms on a surface. All previous atom lasers have been created from atoms coupled out from an existing Bose-Einstein Condensate. There are different approaches but common to them all is that the duration of the output of the atom laser is limited by the size of the initial BEC and they all have a low flux. This leaves the quest to build a continuous high flux atom laser. An alternative approach to a continuous BEC beam is to channel a continuous ultra cold atomic beam into a magnetic guide and then cool this beam down to degeneracy. Cooling down a continuous beam of atoms faces three large problems: The collision rate has to be large enough for effective rethermalization, since evaporative cooling in 2D is not as effective as in 3D and a large thermal conductivity due to atoms with a high angular momentum causes heating downstream in the guide. We have built a 4 meter magnetic guide that is placed on a downward slope with a magnetic barrier in the end. In the guide we load packets of ultra cold rubidium atoms with a frequency rate large enough for the packets to merge together to form a continuous atomic beam. The atomic beam is supersonic and when the beam reaches the end barrier it will return and collide with itself. The collisions lowers the velocity of the beam into subsonic velocities and a shock wave is created between the two velocity regions. In order to conserve number of particle, momentum and enthalpy the density of the atomic beam passing through the shock wave must increase. We have build such a shock wave in an atomic beam and observed the density increase due to this. As an extra feature having a subsonic beam on a downward slope adds an extra density increase due to gravitational compression. Loading ultra cold atoms into a 3D trap from the dense subsonic beam overcomes the problem with 2D cooling and thermal conductivity. This was done and evaporative cooling was applied creating an unprecedented large number rubidium BEC.

•Oct 21, 2011•1 citation

Slow Atomic Beams Manipulation with Magnetic Videotapes

H. Merimeche

Laser cooling methods provide the possibility to obtain very well collimated and slow atomic beams. These intense sources have attracted new interest in the manipulation of atomic trajectories. Atom optical schemes based on the optical dipole force are very attractive, for example in atom lithography where atomic beams are focused by standing wave light elds, to create periodic nanostructures. However, in applications where more complex structures are desirable or decoherence due to spontaneous emission has to be avoided, magnetic atom optical components are more attractive. For example, at and curved atomic mirrors with high reflectivity and low surface rough ness can be built from periodically magnetized videotapes. First, with a collimated and polarized cesium atomic beam from a Zeeman-slower apparatus, we have investigated the deflection of the atomic beam by a sinusoidally magnetized videotape with a period length of 30 μm. From these measurements we have determined the magnetic eld strength at the surface to be 0.05 Tesla. The reflectivity has been found to be consistent with 100%. The very large eld gradients produced by the tape can be exploited to guide atoms on curved trajectories with small radii of curvature. With a radius of 9.5 cm we have obtained a maximum deflection angle of 25° which is limited by technical constraint. Second, we have built a setup based on a 2D-MOT for generating a slow atomic beam with a velocity of 20 m/s. After leaving the optical collimation and the optical polarization stages, the atomic beam is reflected after one bounce onto the videotape up to angles as large as 7°. We exploited the natural curvature of our videotape and we demonstrated the focusing of the atomic beam after one and two bounces depending on the curvature of the videotape. The focal length and the angles of deflection enable to deduce the local radii of curvature. We have confronted our results by testing the focusing of the videotape with a red laser and by performing a numerical simulation which prove the consistency with the atomic beam experiments.

•Jan 1, 2004•1 citation
An atomic beam has been collimated, compressed, and deflected simultaneously by an atomic beam guide based on an tilted one-dimensional magneto-optical trap. Isotope-selected rubidium atoms were extracted from the naturally-mixed thermal atomic beam. We could extract more than 50% of the incident atoms as a deflection beam when we combined this deflection technique with the atomic deceleration using a broadband spectral light. We could manipulate the transverse displacement of the deflected beam precisely by modifying the quadrupole magnetic field. We also observed the well-collimated atomic beam to be channeled into the dipole force potential valleys formed by the standing wave light field.
The fine control of a neutral atomic beam by radiation pressure has opened a new field called atom lithography. In particular, a direct writing method, which focuses an atomic beam with a standing-wave light field into narrow lines, has been demonstrated. A velocity-controlled and isotope-selected atomic beam is essential for improving the performance of this lithography method. An atomic deflection technique using radiation pressure is indispensable for producing such an atomic beam. Here we report on an atomic beam guide using a one-dimensional magneto-optical trap (1D-MOT). First we decelerate atoms whose velocities lie in the range between 250 and 320 m/s. A diode laser (780 nm) is used as the light source for deceleration and its injection current is modulated at 2 MHz. Then the decelerated beam is deflected by a tilted 1D-MOT, which consists of four copper rods and four rectangular mirrors.
We demonstrate an atom laser using all-optical techniques. A Bose-Einstein condensate of rubidium atoms is created by direct evaporative cooling in a quasistatic dipole trap realized with a single, tightly focused CO2-laser beam. An applied magnetic field gradient allows the formation of the condensate in a field-insensitive m(F)=0 spin projection only, which suppresses fluctuations of the chemical potential from stray magnetic fields. A collimated and monoenergetic beam of atoms is extracted from the Bose-Einstein condensate by continuously lowering the dipole trapping potential in a controlled way to form a novel type of atom laser.
The atom laser has long been a holy grail within atom physics and with the creation of an atom laser we hope to bring a similar revolution in to the field of atom optics. With the creation of the Bose-Einstein Condensate (BEC) in 1995 the path to an atom laser was initiated. An atom laser is continues source of BEC. In a Bose condensate all the atoms occupy the same quantum state and can be described by the same wave function and phase. With an atom laser the De Broglie wavelength of atoms can be much smaller than the wavelength of light. Due to the ultimate control over the atoms the atom laser is very interesting for atom optics, lithography, metrology, etching and deposition of atoms on a surface. All previous atom lasers have been created from atoms coupled out from an existing Bose-Einstein Condensate. There are different approaches but common to them all is that the duration of the output of the atom laser is limited by the size of the initial BEC and they all have a low flux. This leaves the quest to build a continuous high flux atom laser. An alternative approach to a continuous BEC beam is to channel a continuous ultra cold atomic beam into a magnetic guide and then cool this beam down to degeneracy. Cooling down a continuous beam of atoms faces three large problems: The collision rate has to be large enough for effective rethermalization, since evaporative cooling in 2D is not as effective as in 3D and a large thermal conductivity due to atoms with a high angular momentum causes heating downstream in the guide. We have built a 4 meter magnetic guide that is placed on a downward slope with a magnetic barrier in the end. In the guide we load packets of ultra cold rubidium atoms with a frequency rate large enough for the packets to merge together to form a continuous atomic beam. The atomic beam is supersonic and when the beam reaches the end barrier it will return and collide with itself. The collisions lowers the velocity of the beam into subsonic velocities and a shock wave is created between the two velocity regions. In order to conserve number of particle, momentum and enthalpy the density of the atomic beam passing through the shock wave must increase. We have build such a shock wave in an atomic beam and observed the density increase due to this. As an extra feature having a subsonic beam on a downward slope adds an extra density increase due to gravitational compression. Loading ultra cold atoms into a 3D trap from the dense subsonic beam overcomes the problem with 2D cooling and thermal conductivity. This was done and evaporative cooling was applied creating an unprecedented large number rubidium BEC.
Laser cooling methods provide the possibility to obtain very well collimated and slow atomic beams. These intense sources have attracted new interest in the manipulation of atomic trajectories. Atom optical schemes based on the optical dipole force are very attractive, for example in atom lithography where atomic beams are focused by standing wave light elds, to create periodic nanostructures. However, in applications where more complex structures are desirable or decoherence due to spontaneous emission has to be avoided, magnetic atom optical components are more attractive. For example, at and curved atomic mirrors with high reflectivity and low surface rough ness can be built from periodically magnetized videotapes. First, with a collimated and polarized cesium atomic beam from a Zeeman-slower apparatus, we have investigated the deflection of the atomic beam by a sinusoidally magnetized videotape with a period length of 30 μm. From these measurements we have determined the magnetic eld strength at the surface to be 0.05 Tesla. The reflectivity has been found to be consistent with 100%. The very large eld gradients produced by the tape can be exploited to guide atoms on curved trajectories with small radii of curvature. With a radius of 9.5 cm we have obtained a maximum deflection angle of 25° which is limited by technical constraint. Second, we have built a setup based on a 2D-MOT for generating a slow atomic beam with a velocity of 20 m/s. After leaving the optical collimation and the optical polarization stages, the atomic beam is reflected after one bounce onto the videotape up to angles as large as 7°. We exploited the natural curvature of our videotape and we demonstrated the focusing of the atomic beam after one and two bounces depending on the curvature of the videotape. The focal length and the angles of deflection enable to deduce the local radii of curvature. We have confronted our results by testing the focusing of the videotape with a red laser and by performing a numerical simulation which prove the consistency with the atomic beam experiments.