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

AIP conference proceedings

Optical frequency standard based upon single laser-cooled indium ion

Warren Nagourney, Justin R. Torgerson, HANS G. DEHMELT

Published Jan 1, 1999• 2 citations
Publisher

Abstract

The current state of our single indium ion work will be presented, with emphasis on the construction of a narrow, solid-state source of tunable UV radiation which will serve as a “clock” laser for the single-ion standard. Indium is shown to be a favorable candidate for a standard with a long term inaccuracy of less than one part in 1017. Its advantages are small systematic errors which are well-understood and relatively straightforward generation of the cooling and “clock” radiation. The stringent requirements on the long term stability of the “flywheel” clock laser and the difficulty in coherently relating the optical clock laser frequency to a convenient microwave source are problems which should soon be overcome.

DOI
10.1063/1.57475

Related papers

Indium Single-Ion Frequency Standard

Warren Nagourney

A single laser-cooled indium ion is a promising candidate for an ultimate resolution optical time or frequency standard. It can be shown that single ions from group IIIA of the periodic table (indium, thallium, etc.) can have extremely small systematic errors. In addition to being free from Doppler, transit-time and collisional shifts, these ions are also quite insensitive to perturbations from ambient magnetic and electric fields (mainly due to the use of a J=0-0 transition for spectroscopy). Of all group IIIA ions, indium seems to be the most practical, since it is heavy enough to have a tolerable intercombination cooling transition rate and (unlike thallium) has transitions which are easily accessible with frequency multiplied continuous-wave lasers. A single indium ion standard has a potential inaccuracy of one part in 10(exp 18) for integration times of 10(exp 6) seconds. We have made substantial progress during the grant period in constructing a frequency standard based upon a single indium ion. At the beginning of the grant period, single indium ions were being successfully trapped, but the lasers and optical systems were inadequate to achieve the desired goal. We have considerably improved the stability of the dye laser used to cool the ions and locked it to a molecular resonance line, making it possible to observe stable cooling-line fluorescence from a single indium ion for reasonable periods of time, as required by the demands of precision spectroscopy. We have substantially improved the single-ion fluorescence signal with significant benefits for the detection efficiency of forbidden transitions using the 'shelving' technique. Finally, we have constructed a compact, efficient UV 'clock' laser and observed 'clock' transitions in single indium ions using this laser system. We will elaborate on these accomplishments.

•Jan 1, 2001•0 citations

Indium single ion optical frequency standard

T. Becker, M. Eichenseer, Alexander Yu. Nevsky +5 more

A single laser cooled ion in a radiofrequency trap can serve as the basis for a highly stable optical frequency standard. We present recent results of our work on single indium ions, using the /sup 1/S/sub 0/ to /sup 3/P/sub 0/ transition at 236.5 nm wave-length as the clock transition. This resonance has a linewidth of only 0.82 Hz where systematic shifts should be controllable on the mHz level. A single In/sup +/ ion is stored in a miniature Paul-Straubel trap and laser cooled to a temperature of about 100 /spl mu/K. The clock transition is excited using a frequency quadrupled Nd:YAG laser. A fractional resolution of 1.3/spl middot/10/sup -13/ has been achieved so far (linewidth of 170 Hz at 1267 THz). The absolute frequency of the clock transition clock transition has been measured with an uncertainty of 2/spl middot/10/sup -13/ using a frequency chain and a methane-stabilized HeNe laser as a reference, that was calibrated with a cesium clock.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Nov 13, 2002•3 citations

Indium single-ion optical frequency standard

Thomas P. Becker, M. Eichenseer, Alexander Yu. Nevsky +5 more

Single laser-cooled ions in radiofrequency traps can serve as the basis for highly stable optical frequency standards. Here we present recent results on In+, using the 1S0 yields 3P0 line at 236.5 nm wavelength as the clock transition. This resonance has a natural linewidth of only 0.82 Hz and systematic shifts should be controllable at the mHz level. A single indium ion is stored in a miniature Paul- Straubel trap and laser cooled to a temperature of about 100 (mu) K. The clock transition is excited using a frequency quadrupled 946 nm Nd:YAG laser. A fractional resolution of 1.3 (DOT) 10-13 has been achieved so far (linewidth of 170 Hz at 1267 THz). The absolute optical frequency of the clock transition has been measured with an uncertainty being less than 3 (DOT) 10-13 using a frequency chain and a methane-stabilized HeNe laser that was calibrated with a cesium clock.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 3, 2001•0 citations

Narrow-linewidth laser system for precise spectroscopy of the indium ion clock transition

Alexander Yu. Nevsky, M. Eichenseer, E. Peik +2 more

Summary form only given. A single laser-cooled indium ion, stored in a radio-frequency trap, is expected to be one of the most promising candidates for the creation of a new generation of optical frequency standards with an anticipated accuracy of up to 10/sup -18/. On the way to achieving such a high level of accuracy, one of the main limitations is the short-term frequency instability of the laser system, used to excite the narrow /sup 1/S/sub 0/-/sup 3/P/sub 0/ In/sup +/ clock transition. Since the signal from the single ion is small, the laser system should posses extremely high frequency stability (on the level of /spl Delta/v/v=10/sup -14//spl divide/10/sup -15/) for averaging times of about one second in order to reduce statistical uncertainties and to minimize the time of experiment. In this paper, we report our recent results on the improvement of the short-term frequency stability of the laser system.

Quantum Electronics and Laser Science Conference•Nov 13, 2002•0 citations

Progress Toward an Optical Frequency Standard Based on a Single Indium Ion

Y. H. Wang, T. Liu, Alois Stejskal +7 more

We report on the current status of the optical frequency standard based on a single 115In+ ion. A single Indium ion is being trapped in a Paul-Strauble type trap and cooled in combination of Doppler cooling and sideband cooling to its lowest vibrational states. To interrogate the1S0-3P0clock transition with high accuracy we demonstrate a Hz-level laser system resonant to this transition. With the current setup we are able to achieve a measured linewidth of the clock transition of 260 Hz. The statistical uncertainty of the absolute frequency measurement is 3×10-13, limited mainly by our reference frequency standard.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Jun 1, 2006•6 citations

The199Hg single ion optical clock: recent progress

U. Tanaka, S. Bize, Carol E. Tanner +6 more

We report on work directed toward the systematic evaluation of an optical frequency standard based on the 2 S 1/2 – 2 D 5/2 transition of a single, laser-cooled, trapped 199 Hg + ion, whose resonance frequency is 1.06 × 10 15 Hz. For the purpose of the evaluation, two 199 Hg + standards have been constructed. In the cooling-laser system built for the second standard, an injection-locking scheme has been applied to a cw Ti:sapphire laser. We also report optical frequency measurements of the clock transition performed over the past 21 months with the first standard. During this term, the variation of the clock transition frequency is found to be less than one part in 10 14 .

Journal of Physics B Atomic Molecular and Optical Physics•Jan 23, 2003•20 citations
The current state of our single indium ion work will be presented, with emphasis on the construction of a narrow, solid-state source of tunable UV radiation which will serve as a “clock” laser for the single-ion standard. Indium is shown to be a favorable candidate for a standard with a long term inaccuracy of less than one part in 1017. Its advantages are small systematic errors which are well-understood and relatively straightforward generation of the cooling and “clock” radiation. The stringent requirements on the long term stability of the “flywheel” clock laser and the difficulty in coherently relating the optical clock laser frequency to a convenient microwave source are problems which should soon be overcome.
A single laser-cooled indium ion is a promising candidate for an ultimate resolution optical time or frequency standard. It can be shown that single ions from group IIIA of the periodic table (indium, thallium, etc.) can have extremely small systematic errors. In addition to being free from Doppler, transit-time and collisional shifts, these ions are also quite insensitive to perturbations from ambient magnetic and electric fields (mainly due to the use of a J=0-0 transition for spectroscopy). Of all group IIIA ions, indium seems to be the most practical, since it is heavy enough to have a tolerable intercombination cooling transition rate and (unlike thallium) has transitions which are easily accessible with frequency multiplied continuous-wave lasers. A single indium ion standard has a potential inaccuracy of one part in 10(exp 18) for integration times of 10(exp 6) seconds. We have made substantial progress during the grant period in constructing a frequency standard based upon a single indium ion. At the beginning of the grant period, single indium ions were being successfully trapped, but the lasers and optical systems were inadequate to achieve the desired goal. We have considerably improved the stability of the dye laser used to cool the ions and locked it to a molecular resonance line, making it possible to observe stable cooling-line fluorescence from a single indium ion for reasonable periods of time, as required by the demands of precision spectroscopy. We have substantially improved the single-ion fluorescence signal with significant benefits for the detection efficiency of forbidden transitions using the 'shelving' technique. Finally, we have constructed a compact, efficient UV 'clock' laser and observed 'clock' transitions in single indium ions using this laser system. We will elaborate on these accomplishments.
A single laser cooled ion in a radiofrequency trap can serve as the basis for a highly stable optical frequency standard. We present recent results of our work on single indium ions, using the /sup 1/S/sub 0/ to /sup 3/P/sub 0/ transition at 236.5 nm wave-length as the clock transition. This resonance has a linewidth of only 0.82 Hz where systematic shifts should be controllable on the mHz level. A single In/sup +/ ion is stored in a miniature Paul-Straubel trap and laser cooled to a temperature of about 100 /spl mu/K. The clock transition is excited using a frequency quadrupled Nd:YAG laser. A fractional resolution of 1.3/spl middot/10/sup -13/ has been achieved so far (linewidth of 170 Hz at 1267 THz). The absolute frequency of the clock transition clock transition has been measured with an uncertainty of 2/spl middot/10/sup -13/ using a frequency chain and a methane-stabilized HeNe laser as a reference, that was calibrated with a cesium clock.
Single laser-cooled ions in radiofrequency traps can serve as the basis for highly stable optical frequency standards. Here we present recent results on In+, using the 1S0 yields 3P0 line at 236.5 nm wavelength as the clock transition. This resonance has a natural linewidth of only 0.82 Hz and systematic shifts should be controllable at the mHz level. A single indium ion is stored in a miniature Paul- Straubel trap and laser cooled to a temperature of about 100 (mu) K. The clock transition is excited using a frequency quadrupled 946 nm Nd:YAG laser. A fractional resolution of 1.3 (DOT) 10-13 has been achieved so far (linewidth of 170 Hz at 1267 THz). The absolute optical frequency of the clock transition has been measured with an uncertainty being less than 3 (DOT) 10-13 using a frequency chain and a methane-stabilized HeNe laser that was calibrated with a cesium clock.
Summary form only given. A single laser-cooled indium ion, stored in a radio-frequency trap, is expected to be one of the most promising candidates for the creation of a new generation of optical frequency standards with an anticipated accuracy of up to 10/sup -18/. On the way to achieving such a high level of accuracy, one of the main limitations is the short-term frequency instability of the laser system, used to excite the narrow /sup 1/S/sub 0/-/sup 3/P/sub 0/ In/sup +/ clock transition. Since the signal from the single ion is small, the laser system should posses extremely high frequency stability (on the level of /spl Delta/v/v=10/sup -14//spl divide/10/sup -15/) for averaging times of about one second in order to reduce statistical uncertainties and to minimize the time of experiment. In this paper, we report our recent results on the improvement of the short-term frequency stability of the laser system.
We report on the current status of the optical frequency standard based on a single 115In+ ion. A single Indium ion is being trapped in a Paul-Strauble type trap and cooled in combination of Doppler cooling and sideband cooling to its lowest vibrational states. To interrogate the1S0-3P0clock transition with high accuracy we demonstrate a Hz-level laser system resonant to this transition. With the current setup we are able to achieve a measured linewidth of the clock transition of 260 Hz. The statistical uncertainty of the absolute frequency measurement is 3×10-13, limited mainly by our reference frequency standard.
We report on work directed toward the systematic evaluation of an optical frequency standard based on the 2 S 1/2 – 2 D 5/2 transition of a single, laser-cooled, trapped 199 Hg + ion, whose resonance frequency is 1.06 × 10 15 Hz. For the purpose of the evaluation, two 199 Hg + standards have been constructed. In the cooling-laser system built for the second standard, an injection-locking scheme has been applied to a cw Ti:sapphire laser. We also report optical frequency measurements of the clock transition performed over the past 21 months with the first standard. During this term, the variation of the clock transition frequency is found to be less than one part in 10 14 .