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Journal of the Optical Society of America B

Journal of the Optical Society of America B


  • Vol. 22, Iss. 5 — May. 1, 2005
  • pp: 943–950

Measurements of temperature scaling laws in an optically dense magneto-optical trap

Andrejs Vorozcovs, Matthew Weel, Scott Beattie, Saviour Cauchi, and A. Kumarakrishnan  »View Author Affiliations

JOSA B, Vol. 22, Issue 5, pp. 943-950 (2005)

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We have studied the temperature scaling laws for the conditions under which a cloud of trapped Rb 85 atoms in the σ + σ configuration makes the transition from the temperature-limited regime to the multiple-scattering regime. Our experimental technique for measuring temperature relies on measuring the ballistic expansion of the cloud after turning off the confining forces and imaging the cloud size as a function of time with two CCD cameras. In the transition regime, the temperature T is shown to depend on the number of atoms N and the peak density n as ( T T o ) N 1 3 and as ( T T o ) n 2 3 , in a manner consistent with theoretical predictions. Here T o is defined as the equilibrium temperature of a low-density optical molasses. In the multiple-scattering regime we find that T Ω 2 ( δ Γ ) , where Ω and δ are the Rabi frequency and the detuning of the trapping laser, respectively, and Γ is the natural linewidth of the cycling transition. We have also measured the ratio of temperatures along the axial and radial directions of the magnetic field gradient coils and find that the temperature is isotropic only if the intensities of the three orthogonal trapping beams are equal, and that the ratio is generally independent of trapping laser intensity and magnetic field gradient. Finally we demonstrate a measurement of the gravitational acceleration precise to 0.1 % by tracking the center of the cloud during ballistic expansion.

© 2005 Optical Society of America

OCIS Codes
(020.7010) Atomic and molecular physics : Laser trapping
(040.1520) Detectors : CCD, charge-coupled device
(140.3320) Lasers and laser optics : Laser cooling
(140.7010) Lasers and laser optics : Laser trapping
(270.1670) Quantum optics : Coherent optical effects
(300.2530) Spectroscopy : Fluorescence, laser-induced

Andrejs Vorozcovs, Matthew Weel, Scott Beattie, Saviour Cauchi, and A. Kumarakrishnan, "Measurements of temperature scaling laws in an optically dense magneto-optical trap," J. Opt. Soc. Am. B 22, 943-950 (2005)

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  1. E. L. Raab, M. Prentiss, A. Cable, S. Chu, and D. E. Pritchard, "Trapping of neutral sodium atoms with radiation pressure," Phys. Rev. Lett. 59, 2631-2634 (1987). [CrossRef] [PubMed]
  2. C. Monroe, W. Swann, H. Robinson, and C. Wieman, "Very cold trapped atoms in a vapor cell," Phys. Rev. Lett. 65, 1571-1574 (1990). [CrossRef] [PubMed]
  3. M. Kasevich and S. Chu, "Atomic interferometry using stimulated Raman transitions," Phys. Rev. Lett. 67, 181-184 (1991). [CrossRef] [PubMed]
  4. C. W. Oates, K. R. Vogel, and J. L. Hall, "High precision linewidth measurement of laser-cooled atoms: resolution of the Na3pP3/22 lifetime discrepancy," Phys. Rev. Lett. 76, 2866-2869 (1996). [CrossRef] [PubMed]
  5. M. H. Anderson, J. R. Ensher, M. R. Matthews, C. E. Wieman, and E. A. Cornell, "Observation of Bose-Einstein condensation in a dilute atomic vapor," Science 269, 198-201 (1995). [CrossRef] [PubMed]
  6. K. B. Davis, M. O. Mewes, M. R. Andrews, N. J. van Druten, D. S. Durfee, D. M. Kurn, and W. Ketterle, "Bose-Einstein condensation in a gas of sodium atoms," Phys. Rev. Lett. 75, 3969-3973 (1995). [CrossRef] [PubMed]
  7. C. G. Townsend, N. H. Edwards, C. J. Cooper, K. P. Zetie, C. J. Foot, A. M. Steane, P. Szriftgiser, H. Perrin, and J. Dalibard, "Phase-space density in the magneto-optical trap," Phys. Rev. A 52, 1423-1440 (1995). [CrossRef] [PubMed]
  8. G. Hillenbrand, C. J. Foot, and K. Burnett, "Heating due to long-range photon exchange interactions between cold atoms," Phys. Rev. A 50, 1479-1489 (1994). [CrossRef] [PubMed]
  9. G. Hillenbrand, K. Burnett, and C. Foot, "Effect of scattered radiation on sub-Doppler cooling," Phys. Rev. A 52, 4763-4786 (1995). [CrossRef] [PubMed]
  10. K. Lindquist, M. Stephens, and C. Wieman, "Experimental and theoretical study of the vapor-cell Zeeman optical trap," Phys. Rev. A 46, 4082-4090 (1992). [CrossRef] [PubMed]
  11. K. E. Gibble, S. Kasapi, and S. Chu, "Improved magneto-optic trapping in a vapor cell," Opt. Lett. 17, 526-528 (1992). [CrossRef] [PubMed]
  12. T. Walker, D. Sesko, and C. Wieman, "Collective behavior of optically trapped neutral atoms," Phys. Rev. Lett. 64, 408-411 (1990). [CrossRef] [PubMed]
  13. A. M. Steane and C. J. Foot, "Laser cooling below the Doppler limit in a magneto-optical trap," Europhys. Lett. 14, 231-236 (1991). [CrossRef]
  14. A. Hope, D. Haubrich, G. Muller, W. G. Kaenders, and D. Meschede, "Neutral cesium atoms in strong magnetic-quadrupole fields at sub-Doppler temperatures," Europhys. Lett. 22, 669-674 (1993). [CrossRef]
  15. C. D. Wallace, T. P. Dinneen, K. Y. N. Tan, A. Kumarakrishnan, P. L. Gould, and J. Javanainen, "Measurements of temperature and spring constant in a magneto-optical trap," J. Opt. Soc. Am. B 11, 703-711 (1994). [CrossRef]
  16. C. Salomon, J. Dalibard, W. D. Phillips, A. Clairon, and S. Guellatti, "Laser cooling of cesium atoms below 3 µK," Europhys. Lett. 12, 683-688 (1990). [CrossRef]
  17. M. Drewsen, Ph. Laurent, A. Nadir, G. Santarelli, A. Clairon, Y. Castin, D. Grison, and C. Salomon, "Investigation of sub-Doppler cooling effects in a cesium magneto-optical trap," Appl. Phys. B: Lasers Opt. 59, 283-298 (1994). [CrossRef]
  18. C. J. Cooper, G. Hillenbrand, J. Rink, C. G. Townsend, K. Zetie, and C. J. Foot, "The temperature of atoms in a magneto-optical trap," Europhys. Lett. 28, 397-402 (1994). [CrossRef]
  19. S. Grego, M. Colla, A. Fioretti, J. H. Muller, P. Verkerk, and E. Arimondo, "A cesium magneto-optical trap for cold collisions studies," Opt. Commun. 132, 519-526 (1996). [CrossRef]
  20. C. Gabbanini, A. Evangelista, S. Gozzini, A. Lucchesini, A. Fioretti, J. H. Muller, M. Colla, and E. Arimondo, "Scaling laws in magneto-optical traps," Europhys. Lett. 37, 251-256 (1997). [CrossRef]
  21. C. Gerz, T. W. Hodapp, P. Jessen, K. M. Jones, W. D. Phillips, C. I. Westbrook, and K. Molmer, "The temperature of optical molasses for two different atomic angular momenta," Europhys. Lett. 21, 661-666 (1993). [CrossRef]
  22. P. D. Lett, W. D. Phillips, S. L. Rolston, C. E. Tanner, R. N. Watts, and C. I. Westbrook, "Optical molasses," J. Opt. Soc. Am. B 6, 2084-2107 (1989). [CrossRef]
  23. J. Dalibard and C. Cohen-Tannoudji, "Laser cooling below the Doppler limit by polarization gradients: simple theoretical models," J. Opt. Soc. Am. B 6, 2023-2045 (1989). [CrossRef]
  24. Y. Castin and K. Molmer, "Monte Carlo wave-function analysis of 3D optical molasses," Phys. Rev. Lett. 74, 3772-3775 (1995). [CrossRef] [PubMed]
  25. D. W. Sesko, T. J. Walker, and C. E. Wieman, "Behavior of neutral atoms in a spontaneous force trap," J. Opt. Soc. Am. B 8, 946-958 (1991). [CrossRef]
  26. G. Spirou, I. Yavin, M. Weel, A. Vorozcovs, A. Kumarakrishnan, P. R. Battle, and R. C. Swanson, "A high-speed-modulated retro-reflector for lasers using an acousto-optic modulator," Can. J. Phys. 81, 625-638 (2003). [CrossRef]
  27. D. S. Weiss, E. Riis, Y. Shevy, P. J. Ungar, and S. Chu, "Optical molasses and multilevel atoms: experiment," J. Opt. Soc. Am. B 6, 2072-2083 (1989). [CrossRef]
  28. D. Guery-Odelin, J. Soeding, P. Desbiolles, and Jean Dalibard, "Strong evaporative cooling of a trapped cesium gas," Opt. Express 2, 323-329 (1998). [CrossRef] [PubMed]
  29. S. Cauchi, A. Vorozcovs, M. Weel, S. Beattie, O. Gagnon, and A. Kumarakrishnan, "Absorption spectroscopy of trapped rubidium atoms," Can. J. Phys. 82, 905-916 (2004). [CrossRef]
  30. M. Vengalattore, R. S. Conroy, and M. G. Prentiss, "Enhancement of phase space density by increasing trap anisotropy in a magneto-optical trap with a large number of atoms," Phys. Rev. Lett. 92, 183001 (2004). [CrossRef] [PubMed]
  31. M. Weel and A. Kumarakrishnan, "Observation of ground-state Ramsey fringes," Phys. Rev. A 67, 061602(R) (2003). [CrossRef]
  32. M. Weel, S. Beattie, I. Chan, E. Rotberg, A. Vorozcovs, and A. Kumarakrishnan, "A precision measurement of atomic recoil using grating echoes," Phys. Rev. Lett., submitted for publication.

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