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

Japanese Journal of Applied Physics

Multireflection of Cold Atoms in a Near-Field Optical Funnel

Akifumi Takamizawa, Haruhiko Ito, Motoichi Ohtsu

Published Oct 15, 2002• 10 citations
Publisher

Abstract

Multireflection of cold Rb atoms occurs inside a reversed triangular hollow prism with a blue-detuned optical near field. We examine it with a probe light beam, using the frequency detuning and the diameter of an excitation light beam as parameters. In the first bounce, the number density of the reflected atoms reaches a maximum of 10 6 atom/cm 3 at a blue detuning of 0.7 GHz when the beam diameter is 4 mm. The Rb atoms repeat reflection with a period of about 15 ms and an efficiency of 83% per bounce. A cold Rb atomic beam with a high flux of 4 × 10 11 atom/(cm 2 ·s) can be generated through a near-field optical funnel composed of the prism.

DOI
10.1143/jjap.41.6215

Related papers

Cold-atom output from a near-field optical funnel

Akifumi Takamizawa, Hajime Ito, Shungo Yamada +1 more

We demonstrated an atom funnel using blue-detuned near-field light. Cold Rb atoms generated by a magneto-optical trap (MOT) were introduced into the funnel and the output atoms were counted by an accumulative MOT detection system. The number of cold Rb atoms outputted from a 200-/spl mu/m exit hole was maximal at a blue detuning of 1.2 GHz under Sisyphus cooling. The flux intensity was estimated to be 10/sup 5/ atoms/cm/sup 2/s. To increase the flux intensity up to 10/sup 13/ atoms/cm/sup 2/s, we made an atom funnel with a 2-/spl mu/m exit hole.

IEEE Conference on Nanotechnology (IEEE NANO)•Jan 24, 2004•0 citations

Deflecting, focusing, and funnelling atoms by near-field light

Hajime Ito, Kazuo Yamamoto, Akifumi Takamizawa +2 more

We describe atom deflection with a slit-type deflector as an elemental technique of precise atom control using near-field light. In the demonstration experiments, cold Rb atoms deflected by repulsive near-field light induced in a 200?nm-wide slit are detected by means of two-step photoionization. Then, we consider a near-field-light lens of atomic de Broglie waves by developing the atom deflector. The feasibility of nanofocusing is shown by numerical analyses with Fourier atom optics. Finally, we describe atom funnels with evanescent light to generate a cold atomic beam required for atom manipulation using nanometric near-field light. The flux intensity of cold Rb atoms outputted from a 240??m outlet is estimated to be 7.5 ? 107?atom?cm?2?s?1 at a blue detuning of 1.2?GHz. In order to increase the flux intensity to 1012?atom?cm?2?s?1, we develop a Si-made funnel with a micron-sized outlet.

Journal of Optics A Pure and Applied Optics•Mar 23, 2006•7 citations

Observation of cold atom output from an evanescent-light funnel

Akifumi Takamizawa, Haruhiko Ito, Shungo Yamada +1 more

We report the demonstration of an atom funnel composed of evanescent light. The flux intensity of cold Rb atoms output from a 240μm exit hole was 7×107atom∕cm2s at a blue detuning of 1.2GHz. Sisyphus cooling doubled the output efficiency. The estimated flux intensity was 1012atom∕cm2s when the exit-hole diameter was 110μm.

Applied Physics Letters•Sep 6, 2004•14 citations

Accumulative Atom Detection by Magneto-Optical Trap for Near-Field Optical Funnel

Akifumi Takamizawa, Haruhiko Ito, Shungo Yamada +1 more

We use a magneto-optical trap as an integrating counter for descending cold atoms. In the case of cold 87 Rb atoms with an initial mean temperature of 9 µK, 60% of the total number of 2.6 × 10 7 are captured after a 26-cm free-fall and trapped for a long time of 270 s. From the capture efficiency and the decay time, the minimum detectable flux intensity of a cold 87 Rb atomic beam is estimated to be 2 × 10 5 atom/cm 2 ·s. The atom-counting system is used for detection and evaluation of a cold atomic beam produced out of a near-field optical funnel.

Japanese Journal of Applied Physics•Jun 15, 2003•4 citations

Atomic funnel with evanescent light

Hajime Ito, K. Sakaki, Wonho Jhe +1 more

We propose an atomic funnel composed of an evanescent-light mirror produced in a conical hollow prism. The funneling of cold Rb atoms released from a magneto-optical trap is simulated in the scheme of the evanescent-light-induced Sisyphus cooling for compensating the heating by gravity. A geometric method of the conversion of a Gaussian light beam into a doughnut-shaped light beam suitable for the atomic funnel is also experimentally demonstrated by means of a double-cone prism. Under the assumption of a proper optical intensity distribution over the inner surface of a specific conical hollow prism, the Monte Carlo simulation including the van der Waals interaction shows that a half of the released Rb atoms can be collected and the mean temperature of the collected atoms is low enough for the application to be guided with a bent hollow optical fiber.

Physical Review A•Jul 1, 1997•77 citations

Generation of a cold atomic beam with a near-field optical funnel

Akifumi Takamizawa, Hajime Ito, Motoichi Ohtsu

A cold Rb atomic beam with a low velocity of 0.10 m/s and a dense flux of 8.3/spl times/10/sup 12/ atom/spl middot/cm/sup 2//s can be generated from a magneto-optical trap by an atom funnel.

Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR)•Nov 13, 2002•1 citation
Multireflection of cold Rb atoms occurs inside a reversed triangular hollow prism with a blue-detuned optical near field. We examine it with a probe light beam, using the frequency detuning and the diameter of an excitation light beam as parameters. In the first bounce, the number density of the reflected atoms reaches a maximum of 10 6 atom/cm 3 at a blue detuning of 0.7 GHz when the beam diameter is 4 mm. The Rb atoms repeat reflection with a period of about 15 ms and an efficiency of 83% per bounce. A cold Rb atomic beam with a high flux of 4 × 10 11 atom/(cm 2 ·s) can be generated through a near-field optical funnel composed of the prism.
We demonstrated an atom funnel using blue-detuned near-field light. Cold Rb atoms generated by a magneto-optical trap (MOT) were introduced into the funnel and the output atoms were counted by an accumulative MOT detection system. The number of cold Rb atoms outputted from a 200-/spl mu/m exit hole was maximal at a blue detuning of 1.2 GHz under Sisyphus cooling. The flux intensity was estimated to be 10/sup 5/ atoms/cm/sup 2/s. To increase the flux intensity up to 10/sup 13/ atoms/cm/sup 2/s, we made an atom funnel with a 2-/spl mu/m exit hole.
We describe atom deflection with a slit-type deflector as an elemental technique of precise atom control using near-field light. In the demonstration experiments, cold Rb atoms deflected by repulsive near-field light induced in a 200?nm-wide slit are detected by means of two-step photoionization. Then, we consider a near-field-light lens of atomic de Broglie waves by developing the atom deflector. The feasibility of nanofocusing is shown by numerical analyses with Fourier atom optics. Finally, we describe atom funnels with evanescent light to generate a cold atomic beam required for atom manipulation using nanometric near-field light. The flux intensity of cold Rb atoms outputted from a 240??m outlet is estimated to be 7.5 ? 107?atom?cm?2?s?1 at a blue detuning of 1.2?GHz. In order to increase the flux intensity to 1012?atom?cm?2?s?1, we develop a Si-made funnel with a micron-sized outlet.
We use a magneto-optical trap as an integrating counter for descending cold atoms. In the case of cold 87 Rb atoms with an initial mean temperature of 9 µK, 60% of the total number of 2.6 × 10 7 are captured after a 26-cm free-fall and trapped for a long time of 270 s. From the capture efficiency and the decay time, the minimum detectable flux intensity of a cold 87 Rb atomic beam is estimated to be 2 × 10 5 atom/cm 2 ·s. The atom-counting system is used for detection and evaluation of a cold atomic beam produced out of a near-field optical funnel.
We propose an atomic funnel composed of an evanescent-light mirror produced in a conical hollow prism. The funneling of cold Rb atoms released from a magneto-optical trap is simulated in the scheme of the evanescent-light-induced Sisyphus cooling for compensating the heating by gravity. A geometric method of the conversion of a Gaussian light beam into a doughnut-shaped light beam suitable for the atomic funnel is also experimentally demonstrated by means of a double-cone prism. Under the assumption of a proper optical intensity distribution over the inner surface of a specific conical hollow prism, the Monte Carlo simulation including the van der Waals interaction shows that a half of the released Rb atoms can be collected and the mean temperature of the collected atoms is low enough for the application to be guided with a bent hollow optical fiber.