Measurement of the calcium ^1P_1−^1D_2 transition rate in a laser-cooled atomic beam

Beverini, N.; Giammanco, F.; Maccioni, Enrico; Strumia, F.; Vissani, Giulio

doi:10.1364/josab.6.002188

Cited by 54 publications

(20 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The alkaline earth metal elements, for instance, have a ns 2 1 S 0 -nsnp 1 P 1 main cooling transition but decays are allowed from the upper level of this transition to metastable D states and subsequently triplet P states. The branching ratios to these states are approximately 1:100 000 for Ca [2], 1:51300 for Sr [3], and 1:330 for Ba [4]. In the cases of Ca and Sr the branching to the metastable D states is sufficiently weak that it is not a limitation to achieve laser cooling although it does limit the MOT lifetime to a few tens of ms.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopy and isotope shifts of the4s3d1D2–
Dammalapati
¹
,
Norris
²
,
Burrows
³

et al. 2010
Phys. Rev. A

View full text Add to dashboard Cite

We investigate a repumping scheme for magneto-optically trapped calcium atoms. It is based on excitation of the 4s3d 1 D 2 -4s5p 1 P 1 transition at 672 nm with an extended cavity diode laser. The effect of the repumping is approximately a factor of three increase in trap lifetime and a doubling of the trapping efficiency from a Zeeman slowed thermal beam. Added to this, the 672-nm laser repumps atoms from an otherwise dark state to yield an overall increase in detected fluorescence signal from the magneto-optic trap (MOT) of more than an order of magnitude. Furthermore, we report isotope shift measurements of the 672-nm transition, for the first time, for four naturally occurring even isotopes. Using available charge radii data, the observed shifts, extending up to 4.3 GHz, display the expected linear dependence in a King plot analysis. The measured shifts are used to determine the isotope shifts of the remaining 41,43,46 Ca isotopes. These might be of interest where less abundant isotopes are used enabling isotope selective repumping, resulting in enhanced trapping and detection efficiencies.

show abstract

Section: Introductionmentioning

confidence: 99%

Spectroscopy and isotope shifts of the4s3d1D2–
Dammalapati
¹
,
Norris
²
,
Burrows
³

et al. 2010
Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…We prepare cold Calcium 3 P 2 atoms in the mK range at very high rates from a magneto-optic trap operating on the principle fluorescence line of the singlet system at 423 nm (called SMOT in the following) [12]. The excited state of the SMOT-transition has a small decay channel leading to the 1 D 2 state (γ 1 = 2180 s −1 [13]) and further on to the 3 P 2 (γ 2 = 96 s −1 ) and 3 P 1 (γ 3 = 300 s −1 ) triplet states (see Fig.1a for relevant Ca levels). While the atoms decaying via 3 P 1 return to the ground state in about 3 ms and can be recycled into the SMOT, those decaying to 3 P 2 represent a permanent loss that limits the SMOT life time to 21 ms.…”

mentioning

confidence: 99%

Magnetic trapping of metastable calcium atoms

2003

View full text Add to dashboard Cite

Metastable calcium atoms, produced in a magneto-optic trap (MOT) operating within the singlet system, are continuously loaded into a magnetic trap formed by the magnetic quadrupole field of the MOT. At MOT temperatures of 3 mK and 240 ms loading time we observe 1.1 × 10 8 magnetically trapped 3 P2 atoms at densities of 2.4×10 8 cm −3 and temperatures of 0.61 mK. In a modified scheme we first load a MOT for metastable atoms at a temperature of 0.18 mK and subsequently release these atoms into the magnetic trap. In this case 240 ms of loading yields 2.4 × 10 8 trapped 3 P2 atoms at a peak density of 8.7 × 10 10 cm −3 and a temperature of 0.13 mK. The temperature decrease observed in the magnetic trap for both loading schemes can be explained only in part by trap size effects.PACS numbers: 32.80. Pj, 42.50.Vk, 42.62.Fi, Earth alkaline atoms provide a unique combination of interesting spectroscopic features connected to their two valence electrons which give rise to singlet and triplet excitations. The singlet systems possess strong principle fluorescence lines well suited for laser cooling with remarkable efficiency. Yet, temperatures are limited to the mK domain, due to the absence of ground state Zeeman structure, a prerequisite for sub-Doppler techniques. The triplet systems, however, have readily accessible narrow band optical transitions that render possible refined laser cooling schemes with the promise of temperatures even beyond the microkelvin range. In fact, such schemes have recently been experimentally realized for strontium and calcium [1,2,3,4]. Owing to their spectroscopic peculiarities such ultracold earth alkaline samples open up new prospects for ultraprecise atomic clocks [5,6,7] and cold collision studies which allow direct comparisons with ab initio theoretical calculations [8,9,10]. The formation of Bose-Einstein condensates (BEC,[11]) for this exciting group of atoms appears particularly desirable.A key technique for obtaining BEC in alkalis and nobel gases has been magnetic trapping. This trapping technique outperforms optical techniques in two ways. It provides well controllable potential wells with sufficient steepness. The regime of high elastic collision rates, a precondition for efficient evaporative cooling, is thus easily accessible. Secondly, the presence of antibinding magnetic sublevels allows to actively force evaporation in a particular effective way by selectively expelling energetic atoms from the trap. The extension of this successful trapping technique to earth alkaline atoms may pave the route to BEC in this atom group. While the singlet ground state of these species lacks magnetic substructure, the ground state of the triplet system typically offers a particularly large Zeeman effect. Specifically, the long-lived 3 P 2 , m J =2 state appears appropriate for mag- * Electronic address: dhansen@physnet.uni-hamburg.de netic trapping and the formation of BEC. Recent calculations for calcium and strontium predict a positive scattering length (and thus stable BEC) for this state [...

show abstract

“…This lifetime is not limited by the imperfect vacuum environment, but by the optical pumping of the 1 D 2 level [24]. The transition from the 1 P 1 level to the 1 D 2 has a probability 10 5 times lower than the probability to decay to the ground state [25]. From the 1 D 2 level the atom can decay to the metastable 3 P 2 level (τ ≈ 2 hours, [26]), to the 3 P 1 or directly to the ground state.…”

Section: Storage Time and Temperaturementioning

confidence: 99%

“…An strategy to increase the lifetime, by decreasing the loss rate and therefore increasing the number of atoms, is to transfer the population of the 1 D 2 level to the 5 1 P 1 level with a repump laser at 672 nm. From the 5 1 P 1 level the atoms decay rapidly to the ground state (1.2 x 10 7 s −1 [25]) and are recaptured. This scheme was demonstrated by the NIST [3] and the Hamburg group [29], where lifetimes of 84 and 72 ms were achieved respectively.…”

Section: Storage Time and Temperaturementioning

confidence: 99%

Calcium magneto-optical trap loaded from a decelerated atomic beam

Filho¹,

Manoel²,

Ortega³

et al. 2003

Braz. J. Phys.

View full text Add to dashboard Cite

We describe a new system for laser cooling and trapping of neutral Calcium atoms employing the 1 S0 − 1 P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580 • C this system can load 1.2 (2) x 10 7 atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.

show abstract

Measurement of the calcium ^1P_1−^1D_2 transition rate in a laser-cooled atomic beam

Cited by 54 publications

References 4 publications

Spectroscopy and isotope shifts of the4s3d1D2–
Dammalapati
¹
,
Norris
²
,
Burrows
³

et al. 2010
Phys. Rev. A

Spectroscopy and isotope shifts of the4s3d1D2–
Dammalapati
¹
,
Norris
²
,
Burrows
³

et al. 2010
Phys. Rev. A

Magnetic trapping of metastable calcium atoms

Calcium magneto-optical trap loaded from a decelerated atomic beam

Contact Info

Product

Resources

About

Measurement of the calcium ^1P_1−^1D_2 transition rate in a laser-cooled atomic beam

Cited by 54 publications

References 4 publications

Spectroscopy and isotope shifts of the4s3d1D2–Dammalapati1, Norris2, Burrows3 et al. 2010Phys. Rev. A

Spectroscopy and isotope shifts of the4s3d1D2–Dammalapati1, Norris2, Burrows3 et al. 2010Phys. Rev. A

Magnetic trapping of metastable calcium atoms

Calcium magneto-optical trap loaded from a decelerated atomic beam

Contact Info

Product

Resources

About

Spectroscopy and isotope shifts of the4s3d1D2–
Dammalapati
¹
,
Norris
²
,
Burrows
³

et al. 2010
Phys. Rev. A

Spectroscopy and isotope shifts of the4s3d1D2–
Dammalapati
¹
,
Norris
²
,
Burrows
³

et al. 2010
Phys. Rev. A