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1.
We report the realization of ytterbium magneto-optical trap (MOT) operating on the dipole-allowed ^1S0 - ^1P1 transition at 398.9nm. The MOT is loaded by a slowed atomic beam produced by a Zeeman slower. All seven stable isotopes of Yb atoms could be trapped separately at different laser detuning values. Over 10^7 174 Yb atoms are collected in the MOT, whereas the atom number of fermionic isotope ^171Yb is roughly 2.3 × 10^6 due to a lower abundance. Without the Zeeman slower the trapped atom numbers are one order of magnitude lower. Both the even and odd isotopes are recognized as excellent candidates of optical clock transition, so the cooling and trapping of ytterbium atoms by the blue MOT is an important step for building an optical clock. 相似文献
2.
We present a high-power and narrow-linewidth laser for intercombination magneto-optical trapping of ytterbium (Yb) atoms using
the 6s2
1S0–6s6p 3P1 transition. The system generates 415 mW of continuous wave laser radiation at 556 nm with a linewidth of less than 100 kHz.
It is based on a commercial 1 W fiber laser with a frequency doubling stage. Up to 58% frequency doubling efficiency is obtained
at an input power of 0.5 W by using a lithium triborate crystal as a nonlinear medium. The system has been successfully used
for laser cooling of Yb atoms.
PACS 42.55.Wd; 42.60.By; 42.79.Nv 相似文献
3.
为了制备适于原子干涉仪实验的低温锂原子样品,开展了锂原子的塞曼减速及与磁光阱囚禁相关的实验研究.设计并实现了一种结构紧凑的腔体内冷式多级线圈叠加的塞曼减速器,将速度小于600 m/s的7Li原子减速到60 m/s,磁光阱装载速率为5×108/s,囚禁原子数目1×109个,原子团的最低温度约为220±30μK.研究了光学黏胶中7Li原子的寿命与囚禁光频率失谐量的关系.这些结果为进一步开展7Li原子亚多普勒冷却、光势阱蒸发冷却以及原子干涉仪实验奠定了基础. 相似文献
4.
Courtillot I Quessada A Kovacich RP Zondy JJ Landragin A Clairon A Lemonde P 《Optics letters》2003,28(6):468-470
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. 相似文献
5.
We describe an experimental setup designed to produce ultracold trapped gas clouds of fermionic 6Li and bosonic 87Rb. This combination of alkali metals has the potential to reach deeper Fermi degeneracy with respect to other mixtures since it allows for improved heat capacity matching which optimizes sympathetic cooling efficiency. Atomic beams of the two species are independently produced and then decelerated by Zeeman slowers. The slowed atoms are collected into a magneto-optical trap and then transferred into a quadrupole magnetic trap. An ultracold Fermi gas with temperature in the 10?3 T F range should be attainable through selective confinement of the two species via a properly detuned laser beam focused in the center of the magnetic trap. 相似文献
6.
O. N. Prudnikov A. V. Taichenachev V. I. Yudin E. M. Rasel 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(12):1420-1428
The possible deep laser cooling of 24Mg atoms in a deep optical lattice in the presence of an additional pumping field resonant to the narrow 3s3s1S0 → 3s3p3P1 (λ = 457 nm) optical transition is studied. Two quantum models of the laser cooling of atoms in the optical trap are compared. One is based on the direct numerical solution to the kinetic quantum equation for an atomic density matrix; it considers both optical pumping and quantum recoil effects during interaction between the atoms and field photons. The second, simplified model is based on decomposing the states of the atoms over the levels of vibration in the optical trap and analyzing the evolution of these states. The comparison allows derivation of optical field parameters (pumping field intensity and detuning) that ensure cooling of the atoms to minimal energies. The conditions for fast laser cooling in an optical trap are found. 相似文献
7.
J. Piilo E. Lundh K.-A. Suominen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(2):211-222
We have developed Monte Carlo wave function simulation schemes to study
cold collisions between magnesium atoms in a strong red-detuned laser field.
In order to address the strong-field problem, we extend the Monte Carlo wave function framework to include the partial wave
structure of the three-dimensional system. The average heating rate due to radiative collisions is calculated with two different
simulation schemes which are described in detail.
We show that the results of the two methods
agree and give estimates for the radiative collision heating rate for 24Mg atoms in a magneto-optical trap based on the 1S0–1P1 atomic laser cooling transition. 相似文献
8.
P. L. Chapovsky 《Journal of Experimental and Theoretical Physics》2006,103(5):711-719
Spectral characteristics of rubidium atoms confined in a dark magneto-optical trap (DMOT) are measured, including probe absorption spectra and atom density as a function of the cooling and repumping laser frequencies. The trap can capture and cool more than 2.5 × 108 rubidium atoms, confining them in a hyperfine state weakly perturbed by the laser beams used to form the trap. The optical density of the trapped atomic cloud approaches 9. A qualitative model of the DMOT operation is presented, based on the experimental results obtained. 相似文献
9.
V. Wippel C. Binder W. Huber L. Windholz M. Allegrini F. Fuso E. Arimondo 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,17(3):285-291
A two element magneto-optical trap (MOT) for Na and 7Li or 6Li is used to cool and trap each of them separately. A fraction of the cold atoms is maintained in the first 2P3/2 excited state by the cooling laser. These excited state atoms are ionized by laser light in the near-UV region, giving rise
to a smaller number of trapped atoms and to different loading parameters. Photoionization cross-sections were derived out
of these data. They are in reasonable agreement with data previously obtained using thermal samples and with theoretical predictions.
Received 21 March 2001 and Received in final form 3 August 2001 相似文献
10.
F. Jessen M. Knufinke S. C. Bell P. Vergien H. Hattermann P. Weiss M. Rudolph M. Reinschmidt K. Meyer T. Gaber D. Cano A. Günther S. Bernon D. Koelle R. Kleiner J. Fortágh 《Applied physics. B, Lasers and optics》2014,116(3):665-671
We describe the preparation of ultracold atomic clouds in a dilution refrigerator. The closed-cycle 3He/4He cryostat was custom made to provide optical access for laser cooling, optical manipulation and detection of atoms. We show that the cryostat meets the requirements for cold atom experiments, specifically in terms of operating a magneto-optical trap, magnetic traps and magnetic transport under ultrahigh vacuum conditions. The presented system is a step toward the creation of a quantum hybrid system combining ultracold atoms and solid-state quantum devices. 相似文献
11.
B. B. Zelener S. A. Saakyan V. A. Sautenkov A. M. Akulshin E. A. Manykin B. V. Zelener V. E. Fortov 《JETP Letters》2014,98(11):670-674
A setup for laser cooling and confining of 7Li atoms in a magneto-optical trap has been built. The possibility of cooling and trapping of 7Li atoms in a wide range of frequency detuning of the cooling laser has been proved experimentally. Independent information on the density and number of ultracold 7Li atoms on various ground-state sublevels, as well as on the temperature of the atoms, has been obtained with the use of a probing tunable laser. This information is important for preparing an ultracold plasma and Rydberg matter. 相似文献
12.
P. L. Chapovsky 《Journal of Experimental and Theoretical Physics》2005,100(5):911-919
The characteristics of a magneto-optical trap (MOT) using small-diameter cooling laser beams are considered. Trapping and cooling of Rb atoms from the surrounding gas of warm atoms takes place in the trap. A compact (140 μm) and stable atomic cloud is obtained with a density of 7 × 1010 cm?3, which is three orders of magnitude higher than the density of the surrounding gas. 相似文献
13.
D. L. Jenkin D. J. McCarron M. P. Köppinger H. W. Cho S. A. Hopkins S. L. Cornish 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,65(1-2):11-18
We report an apparatus and method capable of producing Bose-Einstein condensates (BECs) of ~1 × 106 87Rb atoms, and ultimately designed for sympathetic cooling of 133Cs and the creation of ultracold RbCs molecules. The method combines several elements: (i) the large recapture of a magnetic quadrupole trap from a magneto-optical trap; (ii) efficient forced RF evaporation in such a magnetic trap; (iii) the gain in phase-space density obtained when loading the magnetically trapped atoms into a far red-detuned optical dipole trap, and (iv) efficient evaporation to BEC within the dipole trap. We demonstrate that the system is capable of sympathetically cooling the |F = 1, m F = ?1〉 and |1,0? sublevels with |1, +1〉 atoms. Finally we discuss the applicability of the method to sympathetic cooling of 133Cs with 87Rb. 相似文献
14.
A. di Stefano D. Wilkowski J.H. Müller E. Arimondo 《Applied physics. B, Lasers and optics》1999,69(4):263-268
We have operated a magneto-optical trap and optical molasses for the laser cooling of cesium atoms on the basis of a five-beam
laser configuration. For the magneto-optical trap two laser beams counterpropagate along the axis of a quadrupole trap and
the remaining three beams propagate in the orthogonal plane at 120° to each other. The same optical configuration was used
for the optical molasses. We have tested the efficiency in atom collection and the temperatures reached in both cooling processes.
In comparison to previous results on a six-beam configuration, a lower number of atoms is collected, while comparable densities
are realized. The atomic temperatures have been measured through a delayed shadow-image technique, where one of the running-wave
cooling beams produces an absorptive image of the atoms on a camera.
Received: 14 January 1999 / revised version: 23 June 1999 / Published online: 8 September 1999 相似文献
15.
J. Szczepkowski E. Paul-Kwiek G. Auböck L. Holler C. Binder L. Windholz 《The European physical journal. Special topics》2007,144(1):265-271
We report the results of trap depth calculations based on the
semiclassical theory of interaction of light field with atom in
magneto-optical trap (MOT). In our model of magneto-optical trap we take
into account Zeeman shift of ground and excited states in local magnetic
field and only Doppler cooling force are considered.
The calculated trap depth has been compared with value of trap depth
estimated from experimental results for 7Li. 相似文献
16.
Laser cooling on weak transitions is a useful technique for reaching ultracold temperatures in atoms with multiple valence electrons. However, for strongly magnetic atoms a conventional narrow-line magneto-optical trap (MOT) is destabilized by competition between optical and magnetic forces. We overcome this difficulty in Er by developing an unusual narrow-line MOT that balances optical and magnetic forces using laser light tuned to the blue side of a narrow (8 kHz) transition. The trap population is spin polarized with temperatures reaching below 2 muK. Our results constitute an alternative method for laser cooling on weak transitions, applicable to rare-earth-metal and metastable alkaline earth elements. 相似文献
17.
D. Sukachev K. Chebakov A. Sokolov A. Akimov N. Kolachevsky V. Sorokin 《Optics and Spectroscopy》2011,111(4):633-638
We demonstrated laser cooling and trapping of thulium atoms at sub-Doppler temperatures in a magneto-optical trap (MOT). Up
to 3 × 106 thulium atoms were trapped in the MOT at temperatures down to 25(5) μK which is approximately 10 times lower than the Doppler
limit. The lifetime of atoms in the MOT varied between 0.3–1.5 s and was restricted mostly by optical leaks from the upper
cooling level. The lower limit for the leaking rate was estimated to be 22(6) s−1. Due to a big magnetic moment of Tm atoms, a part of them were trapped in a magnetic trap from the quadrupole field of the
MOT. We observed about 3 × 104 purely magnetically trapped atoms at temperature of 25 μK with a lifetime in the trap of 0.5 s. Also we set up a “dark” MOT
consisting of six crossed hollow beams which increased the number of trapped atoms by a factor of 5 leading to 1.5 × 107 atoms at the expense of higher temperature. 相似文献
18.
Autler-Townes doublet in the absorption spectra for the transition between excited states of cold cesium atoms 下载免费PDF全文
Autler-Townes splitting in absorption spectra of the excited states 6 2 P 3/2-8 2 S 1/2 of cold cesium atoms confined in a magneto-optical trap has been observed.Experimental data of the Autler-Townes splitting fit well to the dressed-atom theory,by which the fact of the cold atoms dressed by cooling/trapping laser beams is revealed.The results of the theoretical fitting with experiment not only told us the effective Rabi frequency cold atoms experienced,but also could be used for measuring the probability amplitudes of the dressed states. 相似文献
19.
D. Sukachev A. Sokolov K. Chebakov A. Akimov N. Kolachevsky V. Sorokin 《JETP Letters》2010,92(10):703-706
Sub-Doppler laser cooling in a magneto-optical trap for thulium atoms at a wavelength of 410.6 nm has been experimentally
studied. Without any dedicated molasses period of sub-Doppler cooling, the cloud of 3 × 106 atoms at a temperature of 25(5) μK was observed. The measured temperature is significantly lower than the Doppler limit of
240 μK for the cooling transition at 410.6 nm. The high efficiency of the sub-Doppler cooling process is due to a near-degeneracy
of the Landé g-factors of the lower 4f
136s
2 (J = 7/2) and the upper 4f
125d
3/26s
2 (J = 9/2) cooling levels. 相似文献
20.
Experimental investigation of evaporative cooling mixture of bosonic 87Rb and fermionic 40K atoms with microwave and radio frequency radiation 下载免费PDF全文
We investigate sympathetic cooling fermions 40K by evaporatively cooling bosonic 87Rb atoms in a magnetic trap with microwave and radio frequency induced evaporations in detail. The mixture of bosonic and fermionic atoms is prepared in their polarized spin states |F=9/2, mF=9/2> for 40K and |F=2, mF=2> for 87Rb, which is trapped in Quadrupole--Ioffe--Configuration trap. Comparing microwave with radio frequency evaporatively cooling bosonic 87Rb atoms with sympathetically cooling Fermi gas 40K, we find that the presence of rubidium atoms in the |2,1> Zeeman states, which are generated in the evaporative process, gives rise to a significant loss of 40K due to inelastic collisions. Thus, the rubidium atoms populated in the |2, 1> Zeeman states should be removed in order to effectively perform sympathetically cooling 40K with the evaporatively cooled 87Rb atoms. 相似文献