Optics Letters

Direct frequency-comb spectroscopy of a dipole-forbidden clock transition in trapped Ca^+40 ions

Anne Lisa Wolf, Jonas Morgenweg, Jeroen C. J. Koelemeij, Steven A. van den Berg, Wim Ubachs, K. S. E. Eikema

Published Dec 23, 2010• 14 citations

Abstract

We demonstrate direct frequency-comb (FC) spectroscopy of the dipole-forbidden 4s(2)S(1/2)-3d(2)D(5/2) transition in trapped (40)Ca(+) ions using an unamplified FC laser. The excitation is detected with nearly 100% efficiency using a shelving scheme in combination with single-ion imaging. The method demonstrated here has the potential to reach hertz-level accuracy, if a hertz-level linewidth FC is used in combination with confinement in the Lamb-Dicke regime.

DOI: 10.1364/ol.36.000049

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Optics Letters

Direct frequency-comb spectroscopy of a dipole-forbidden clock transition in trapped Ca^+40 ions

Anne Lisa Wolf, Jonas Morgenweg, Jeroen C. J. Koelemeij, Steven A. van den Berg, Wim Ubachs, K. S. E. Eikema

Published Dec 23, 2010• 14 citations

Publisher

Abstract

DOI: 10.1364/ol.36.000049

Related papers

Direct frequency comb spectroscopy in trapped 40Ca+ ions on a dipoleforbidden clock transition

Anne Lisa Wolf, Jonas Morgenweg, Jeroen C. J. Koelemeij +3 more

Optical frequency combs (FCs) have revolutionised ultra-high precision metrology by providing a link between optical and microwave frequencies. While FCs are traditionally used for calibrating a CW probe-laser, also direct frequency comb spectroscopy (DFCS) is possible. We have recently demonstrated the versatility of DFCS performed in the environment of an ion trap, combining the broad spectral range of a Ti: sapphire FC with the feasibility of trapping and (sympathetic) cooling of different ion species. In the presented contribution it is shown that by employing single-ion imaging, this technique can be extended even to dipole-forbidden transitions, despite the low power per unamplified comb mode of ~0.1 μW.Optical frequency combs (FCs) have revolutionised ultra-high precision metrology by providing a link between optical and microwave frequencies. While FCs are traditionally used for calibrating a CW probe-laser, also direct frequency comb spectroscopy (DFCS) is possible. We have recently demonstrated the versatility of DFCS performed in the environment of an ion trap, combining the broad spectral range of a Ti: sapphire FC with the feasibility of trapping and (sympathetic) cooling of different ion species. In the presented contribution it is shown that by employing single-ion imaging, this technique can be extended even to dipole-forbidden transitions, despite the low power per unamplified comb mode of ~0.1 μW.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)May 1, 20111 citation

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Conference on Lasers and Electro-OpticsAug 29, 20050 citations

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Chinese Science BulletinMar 1, 20139 citations

The progress of the precision spectroscopy with single trapped and laser cooled 40Ca+ ion

Hua Guan, 高克林, Yao HUANG

The experimental study at Wuhan Institute of Physics and Mathematics (WIPM), Chinese Academy of Scienses (CAS) on the precision spetroscopy based on single trapped Ca+ ion is described in this paper. A single Ca+ ion is trapped in a miniature Paul trap and laser cooled to Lamb-Dicke regime, and the ion can be trapped more than 2 months. The linewidth of the 729 nm laser for probing the Ca+ 4s2S1/2-3d2D5/2 clock transition is reduced to lessthan 1 Hz by locked to a super cavity, and the 729 nm laser can be locked more than 1 month continuously. Two similar Ca + ion optical frequency standards are set up for frequency comparison. The systematic uncertainty is evaluated to be <6 ´ 10−17 for both ftrquency standards. The frequency difference of two frequency standards is measured to be 3.0 (5.5) ´ 10−17 within 42 d. The Allan deviation for a single clock is measured to be 1×10−14τ−1/2 with a 3-d-continuous comparison, the stability for a reaches 7 ´ 10−17 at an averaging time of 20000 s. Meanwhile, the absolute frequency of the Ca+ 4s2S1/2-3d2D5/2 clock transition is measured to be 411042129776401.7(1.1) Hz with respect to the SI second through the Global Positioning System (GPSx). The precision spectroscopy experiments are carried out based on the single Ca+ ion system. The magic wavelengths for the Ca+ optical frequency standardare measured to be λ|mj|=1/2=395.7992(7) nm and λ|mj|=3/2=395.7990(7) nm, which agrees with theoretical calculation made by Tang et al. The lifetime of the 3d2D5/2 is measured to be 1174(10) ms, which is agree with the experimental measurement made by University of Oxford and University of Innsbruck and the recent theoretical calculation made by Sahoo.The experimental study at Wuhan Institute of Physics and Mathematics (WIPM), Chinese Academy of Scienses (CAS) on the precision spetroscopy based on single trapped Ca+ ion is described in this paper. A single Ca+ ion is trapped in a miniature Paul trap and laser cooled to Lamb-Dicke regime, and the ion can be trapped more than 2 months. The linewidth of the 729 nm laser for probing the Ca+ 4s2S1/2-3d2D5/2 clock transition is reduced to lessthan 1 Hz by locked to a super cavity, and the 729 nm laser can be locked more than 1 month continuously. Two similar Ca + ion optical frequency standards are set up for frequency comparison. The systematic uncertainty is evaluated to be <6 ´ 10−17 for both ftrquency standards. The frequency difference of two frequency standards is measured to be 3.0 (5.5) ´ 10−17 within 42 d. The Allan deviation for a single clock is measured to be 1×10−14τ−1/2 with a 3-d-continuous comparison, the stability for a reaches 7 ´ 10−17 at an averaging time of 20000 s. Meanwhile, the absolute frequency of the Ca+ 4s2S1/2-3d2D5/2 clock transition is measured to be 411042129776401.7(1.1) Hz with respect to the SI second through the Global Positioning System (GPSx). The precision spectroscopy experiments are carried out based on the single Ca+ ion system. The magic wavelengths for the Ca+ optical frequency standardare measured to be λ|mj|=1/2=395.7992(7) nm and λ|mj|=3/2=395.7990(7) nm, which agrees with theoretical calculation made by Tang et al. The lifetime of the 3d2D5/2 is measured to be 1174(10) ms, which is agree with the experimental measurement made by University of Oxford and University of Innsbruck and the recent theoretical calculation made by Sahoo.

Zhongguo kexue. Wulixue Lixue TianwenxueJun 17, 20160 citations

Hertz-level measurement of the 40 Ca + 4s 2S1/2 – 3d 2D5/2 clock transition frequency with respect to the SI second through the Global Positioning System

Yao Huang, Jian Zhong Cao, P. Liu +6 more

We have measured the absolute frequency of a clock transition at the 10${}^{\ensuremath{-}15}$ level with a single, trapped, laser-cooled ${}^{40}$ Ca ${}^{+}$ ion in a miniature Paul trap. In our measurement, an optical frequency comb is referenced to a hydrogen maser, which is calibrated to the SI second through the Global Positioning System (GPS). By analyzing the experimental data obtained within 32 days of a total averaging time $>$2 $\ifmmode\times\else\texttimes\fi{}$ 10 ${}^{6}$ s, the absolute frequency of the ${}^{40}$ Ca ${}^{+}$ 4 $s$ ${}^{2}\phantom{\rule{-0.16em}{0ex}}{S}_{1/2}$ --3 $d$ ${}^{2}\phantom{\rule{-0.16em}{0ex}}{D}_{5/2}$ clock transition is measured as 411 042 129 776 393.0 (1.6) Hz with a fractional uncertainty of 3.9 $\ifmmode\times\else\texttimes\fi{}$ 10${}^{\ensuremath{-}15}$.We have measured the absolute frequency of a clock transition at the 10${}^{\ensuremath{-}15}$ level with a single, trapped, laser-cooled ${}^{40}$Ca${}^{+}$ ion in a miniature Paul trap. In our measurement, an optical frequency comb is referenced to a hydrogen maser, which is calibrated to the SI second through the Global Positioning System (GPS). By analyzing the experimental data obtained within 32 days of a total averaging time $>$2 $\ifmmode\times\else\texttimes\fi{}$ 10${}^{6}$ s, the absolute frequency of the ${}^{40}$Ca${}^{+}$ 4$s$ ${}^{2}\phantom{\rule{-0.16em}{0ex}}{S}_{1/2}$--3$d$ ${}^{2}\phantom{\rule{-0.16em}{0ex}}{D}_{5/2}$ clock transition is measured as 411 042 129 776 393.0 (1.6) Hz with a fractional uncertainty of 3.9 $\ifmmode\times\else\texttimes\fi{}$ 10${}^{\ensuremath{-}15}$.

arXiv:1111.5174Physical Review AMar 23, 201261 citations

We have measured the absolute frequency of a clock transition at the 10${}^{\ensuremath{-}15}$ level with a single, trapped, laser-cooled

{}^{40}

{}^{+}

ion in a miniature Paul trap. In our measurement, an optical frequency comb is referenced to a hydrogen maser, which is calibrated to the SI second through the Global Positioning System (GPS). By analyzing the experimental data obtained within 32 days of a total averaging time $>$2 $\ifmmode\times\else\texttimes\fi{}$ 10

{}^{6}

s, the absolute frequency of the

{}^{40}

{}^{+}

s

{}^{2}\phantom{\rule{-0.16em}{0ex}}{S}_{1/2}

--3

d

{}^{2}\phantom{\rule{-0.16em}{0ex}}{D}_{5/2}

clock transition is measured as 411 042 129 776 393.0 (1.6) Hz with a fractional uncertainty of 3.9 $\ifmmode\times\else\texttimes\fi{}$ 10${}^{\ensuremath{-}15}$.