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Laser cooling in an optical lattice that employs Raman transitions

R. Zhang, Natalya V. Morrow, P. R. Berman +1 more

We demonstrate laser cooling in an optical lattice that employs Raman transitions. Four laser beams with different frequencies form a one-dimensional lattice with a basic lattice period that is a factor of 2 less than in standard optical lattices. Rb atoms are cooled to $8\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{K}$. We measure the intensity- and detuning-dependence of the cooling mechanism. Our experimental results agree well with theoretical models.

Physical Review AOct 28, 200516 citations

Laser cooling in an optical lattice that employs Raman transitions (4 pages)

R. Zhang, Natalya V. Morrow, P. R. Berman

Physical Review AJan 1, 20050 citations

Transition of laser cooling between standard and Raman optical lattices

R. Zhang, Rachel Sapiro, Natalya V. Morrow +1 more

Reduced-period optical lattices based on Raman transitions allow for sub-Doppler laser cooling. An important parameter of this Raman optical lattice is the frequency difference ${\ensuremath{\Delta}}_{\mathrm{d}}$ between two virtual energy levels involved in the atom-field interaction scheme. In this work, we use experimental time-of-flight data and quantum simulations to characterize laser cooling in the Raman lattice as a function of ${\ensuremath{\Delta}}_{\mathrm{d}}$. Two different domains of laser cooling are identified. For small ${\ensuremath{\Delta}}_{\mathrm{d}}$, atoms are cooled due to a well-known mechanism that also occurs in standard optical lattices. For large ${\ensuremath{\Delta}}_{\mathrm{d}}$, atoms are cooled based on Raman transitions. We study the transition between the two domains of laser cooling in detail.Reduced-period optical lattices based on Raman transitions allow for sub-Doppler laser cooling. An important parameter of this Raman optical lattice is the frequency difference ${\ensuremath{\Delta}}_{\mathrm{d}}$ between two virtual energy levels involved in the atom-field interaction scheme. In this work, we use experimental time-of-flight data and quantum simulations to characterize laser cooling in the Raman lattice as a function of ${\ensuremath{\Delta}}_{\mathrm{d}}$. Two different domains of laser cooling are identified. For small ${\ensuremath{\Delta}}_{\mathrm{d}}$, atoms are cooled due to a well-known mechanism that also occurs in standard optical lattices. For large ${\ensuremath{\Delta}}_{\mathrm{d}}$, atoms are cooled based on Raman transitions. We study the transition between the two domains of laser cooling in detail.

Physical Review ASep 13, 20062 citations

Cooling in reduced period optical lattices: Non-zero Raman detuning

Vladimir S. Malinovsky, P. R. Berman

arXiv:physics/0605052Optics CommunicationsMay 26, 20060 citations

Laser cooling and localization measurements in a Raman optical lattice

Rachel Sapiro, Rui Zhang, Natalya V. Morrow +2 more

Bulletin of the American Physical SocietyMay 17, 20060 citations

Cold neutral atoms in optical lattices

Rui Zhang

In this thesis, I study the properties of cold neutral atoms, including Bose-Einstein condensates (BEC), inside periodic light-shift potentials created by optical lattices. In the first part, a new optical-lattice scheme, employing Raman transitions, hereafter referred to as a Raman Optical Lattice (ROL), is investigated. This optical lattice possesses a novel sub-Doppler cooling mechanism and a reduced periodicity. Both theoretical and experimental results con¯rm these two characteristics of the ROL. In the second half of the thesis, instead of thermal atoms, optical lattices are loaded with condensate atoms. Our BEC apparatus and the procedure towards forming a BEC are described in detail. After the achievement of the BEC, a 1D far-detuned optical lattice is applied to the BEC. A number of phenomena are observed, including Kapitza-Dirac diffraction, thermal atom interference, atom interferometry, Bloch oscillations, and a superfluid to Mott-insulator transition. Finally a brief discussion about future work is given.In this thesis, I study the properties of cold neutral atoms, including Bose-Einstein condensates (BEC), inside periodic light-shift potentials created by optical lattices. In the first part, a new optical-lattice scheme, employing Raman transitions, hereafter referred to as a Raman Optical Lattice (ROL), is investigated. This optical lattice possesses a novel sub-Doppler cooling mechanism and a reduced periodicity. Both theoretical and experimental results con¯rm these two characteristics of the ROL. In the second half of the thesis, instead of thermal atoms, optical lattices are loaded with condensate atoms. Our BEC apparatus and the procedure towards forming a BEC are described in detail. After the achievement of the BEC, a 1D far-detuned optical lattice is applied to the BEC. A number of phenomena are observed, including Kapitza-Dirac diffraction, thermal atom interference, atom interferometry, Bloch oscillations, and a superfluid to Mott-insulator transition. Finally a brief discussion about future work is given.

Jan 1, 20081 citation

Raman optical lattice

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Raman optical lattice

Abstract

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