© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Journal of Experimental and Theoretical Physics

Secondary laser cooling of strontium-88 atoms

S A Strelkin, Ksenia Yu. Khabarova, A. A. Galyshev, O I Berdasov, A Yu Gribov, N. Kolachevsky, Sergey N. Slyusarev

Published Jul 1, 2015• 4 citations

Abstract

The secondary laser cooling of a cloud of strontium-88 atoms on the 1 S 0–3 P 1 (689 nm) intercombination transition captured into a magneto-optical trap has been demonstrated. We describe in detail the recapture of atoms from the primary trap operating on the strong 1 S 0–1 P 1 (461 nm) transition and determine the recapture coefficient κ, the number of atoms, and their temperature in the secondary trap as a function of experimental parameters. A temperature of 2 µK has been reached in the secondary trap at the recapture coefficient κ = 6%, which confirms the secondary cooling efficiency and is sufficient to perform metrological measurements of the 1 S 0–3 P 1 (698 nm) clock transition in an optical lattice.

DOI: 10.1134/s1063776115060205

Related papers

Magneto-Optical Trapping of 88 Sr atoms with 689 nm Laser

Qiang Wang, Bai-Ke Lin, Yang Chun Zhao +6 more

We report the experimental realization of strontium magneto-optical trap (MOT) operating on the intercombination transition 1 S 0 − 3 P 1 at 689 nm, namely red MOT. A 689 nm laser used for cooling and trapping is injection locked to a master laser, whose linewidth is narrowed to 150 Hz by locking to a high finesse optical reference cavity. 88 Sr atoms pre-cooled and trapped by the broad 1 S 0 − 1 P 1 transition at 461 nm are transferred to the red MOT with the help of a time sequence controller. The transfer ratio is about 20% and the red MOT's temperature is estimated to be less than 20 μK by the time-of-flight (TOF) image analysis.

Chinese Physics Letters•Mar 1, 2011•10 citations

Narrow Line Cooling of 88Sr Atoms in the Magneto-optical Trap for Precision Frequency Standard

S A Strelkin, A. A. Galyshev, O I Berdasov +5 more

We report on our progress toward the realization of a Strontium optical lattice clock, which is under development at VNIIFTRI as a part of GLONASS program. We’ve prepared the narrow line width laser system for secondary cooling of 88Sr atoms which allows us to reach atom cloud temperature below 3 μK after second cooling stage.

Physics Procedia•Jan 1, 2015•3 citations

Secondary laser cooling and capturing of thulium atoms in traps

Денис Дмитриевич Сукачев, Елена Сергеевна Калганова, А. В. Соколов +5 more

Secondary laser cooling has been realised on the weak dipole transition 4f13(2Fo)6s2, J = 7/2, F=4 → 4f12(3H6) 5d5/26s2, J' = 9/2, F' = 5 with the wavelength of 530.7 nm and natural width of 350 kHz. The temperature of the atomic cloud in a magnetooptical trap (MOT) was 30 μK at the lifetime of 2 s and the number of atoms 105. Approximately 1% of atoms from the MOT have been reloaded to an optical dipole trap and to one-dimensional optical lattice at the wavelength of 532 nm. The atom lifetime in the optical lattice was 320 ms. We propose to employ thulium atoms captured in an optical lattice as an optical frequency reference.

Quantum Electronics•Jun 30, 2014•23 citations

Ultracold 88Sr atoms for an optical lattice clock

Thomas Legero, J. S. Raaj Vellore Winfred, F. Riehle +1 more

This paper reports results of cooling and trapping of88Sr for future use in an optical lattice clock. Strontium atoms are cooled to ultra-cold temperatures using a two-stage cooling process. In the first stage, atoms are captured from a Zeeman-slowed atomic beam and cooled to 2 mK in a magneto optical trap operated on the1So-1P1transition at 461 nm. The second cooling stage utilizes the spin forbidden1So-3P1transition at 689 nm. To reach ultra-cold temperatures, 50 ms of broadband cooling is followed by 28 ms long single frequency cooling. The transfer efficiency from the first to the second cooling stage was measured to be 23%, leaving 7 x 106 atoms at a temperature of 1 muK. The atomic cloud is overlapped with a horizontally oriented 1-D far-off resonance optical dipole trap (FORT) at 813 nm with an effective potential depth of 25 muK. Due to equal light shifts of the1Soand the3P1state simultaneous Doppler cooling during the atom loading into the FORT is possible which leads to a transfer efficiency into the dipole trap of up to 60%.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•May 1, 2007•4 citations

Near-recoil-limited temperatures obtained by laser trapping on the narrow /sup 1/S/sub 0/-/sup 3/P/sub 1/ intercombination transition of neutral strontium

Kurt R. Vogel, T. Dinneen, Alan C. Gallagher +1 more

About 2/spl times/10/sup 7/ neutral strontium atoms have been loaded into a magneto-optical trap (MOT) that uses the narrow (/spl Gamma/=2/spl pi/ 7 kHz) intercombination line at 689 nm as the cycling transition. The atoms are second-stage laser cooled to /spl sim/10 /spl mu/K from an initial 5 mK atomic sample (/spl sim/5/spl times/10/sup 7/ atoms), generated in a vapor cell MOT that employs the strong (/spl Gamma/=2/spl pi/ 32 MHz) cycling transition at 461 nm. To demonstrate the low temperatures of these atoms, optical Ramsey spectroscopy is performed upon the /sup 1/S/sub 0/-/sup 3/P/sub 1/ transition using only two excitation pulses; the time dependence of the fringe contrast indicates an RMS velocity of 3 cm/s for the 689 nm MOT-cooled sample.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Jan 22, 2003•1 citation

Efficient cooling and trapping of strontium atoms

Irène Ventrillard, Audrey Quessada, Richard P. Kovacich +4 more

We report the capture of cold strontium atoms in a magneto-optical trap (MOT) at a rate of 4 x 10(10) atoms/s. The MOT is loaded from an atomic beam decelerated by a Zeeman slower operating with a focused laser beam. The 461-nm laser, used for both cooling and trapping, was generated by sum-frequency mixing in a KTP crystal with diode lasers at 813 nm and a Nd:YAG laser at 1064 nm. As much as 115 mW of blue light was obtained.

Optics Letters•Mar 15, 2003•48 citations

The secondary laser cooling of a cloud of strontium-88 atoms on the 1 S 0–3 P 1 (689 nm) intercombination transition captured into a magneto-optical trap has been demonstrated. We describe in detail the recapture of atoms from the primary trap operating on the strong 1 S 0–1 P 1 (461 nm) transition and determine the recapture coefficient κ, the number of atoms, and their temperature in the secondary trap as a function of experimental parameters. A temperature of 2 µK has been reached in the secondary trap at the recapture coefficient κ = 6%, which confirms the secondary cooling efficiency and is sufficient to perform metrological measurements of the 1 S 0–3 P 1 (698 nm) clock transition in an optical lattice.

We report the experimental realization of strontium magneto-optical trap (MOT) operating on the intercombination transition 1 S 0 − 3 P 1 at 689 nm, namely red MOT. A 689 nm laser used for cooling and trapping is injection locked to a master laser, whose linewidth is narrowed to 150 Hz by locking to a high finesse optical reference cavity. 88 Sr atoms pre-cooled and trapped by the broad 1 S 0 − 1 P 1 transition at 461 nm are transferred to the red MOT with the help of a time sequence controller. The transfer ratio is about 20% and the red MOT's temperature is estimated to be less than 20 μK by the time-of-flight (TOF) image analysis.

Secondary laser cooling has been realised on the weak dipole transition 4f13(2Fo)6s2, J = 7/2, F=4 → 4f12(3H6) 5d5/26s2, J' = 9/2, F' = 5 with the wavelength of 530.7 nm and natural width of 350 kHz. The temperature of the atomic cloud in a magnetooptical trap (MOT) was 30 μK at the lifetime of 2 s and the number of atoms 105. Approximately 1% of atoms from the MOT have been reloaded to an optical dipole trap and to one-dimensional optical lattice at the wavelength of 532 nm. The atom lifetime in the optical lattice was 320 ms. We propose to employ thulium atoms captured in an optical lattice as an optical frequency reference.

This paper reports results of cooling and trapping of88Sr for future use in an optical lattice clock. Strontium atoms are cooled to ultra-cold temperatures using a two-stage cooling process. In the first stage, atoms are captured from a Zeeman-slowed atomic beam and cooled to 2 mK in a magneto optical trap operated on the1So-1P1transition at 461 nm. The second cooling stage utilizes the spin forbidden1So-3P1transition at 689 nm. To reach ultra-cold temperatures, 50 ms of broadband cooling is followed by 28 ms long single frequency cooling. The transfer efficiency from the first to the second cooling stage was measured to be 23%, leaving 7 x 106 atoms at a temperature of 1 muK. The atomic cloud is overlapped with a horizontally oriented 1-D far-off resonance optical dipole trap (FORT) at 813 nm with an effective potential depth of 25 muK. Due to equal light shifts of the1Soand the3P1state simultaneous Doppler cooling during the atom loading into the FORT is possible which leads to a transfer efficiency into the dipole trap of up to 60%.

About 2/spl times/10/sup 7/ neutral strontium atoms have been loaded into a magneto-optical trap (MOT) that uses the narrow (/spl Gamma/=2/spl pi/ 7 kHz) intercombination line at 689 nm as the cycling transition. The atoms are second-stage laser cooled to /spl sim/10 /spl mu/K from an initial 5 mK atomic sample (/spl sim/5/spl times/10/sup 7/ atoms), generated in a vapor cell MOT that employs the strong (/spl Gamma/=2/spl pi/ 32 MHz) cycling transition at 461 nm. To demonstrate the low temperatures of these atoms, optical Ramsey spectroscopy is performed upon the /sup 1/S/sub 0/-/sup 3/P/sub 1/ transition using only two excitation pulses; the time dependence of the fringe contrast indicates an RMS velocity of 3 cm/s for the 689 nm MOT-cooled sample.