Perturbation-free Spectroscopy of Atoms in an Optical Trap

S. Aubin, Steven Christe, Boris Peker +1 more

Summary form only given. Precision optical spectroscopy requires good control over the motion of the atoms to reduce Doppler broadening. It also benefits from long interaction times between the probe radiation and the atoms in a perturbation-free environment. We have implemented an optical trap that captures cold atoms in a region of darkness. Such a set-up is critical for measuring the fundamental interactions of nature through precise spectroscopic studies.

C. Gabbanini

Mikkel F. Andersen, Ariel Kaplan, Tzahi Grünzweig +1 more

We discuss a recently demonstrated type of microwave spectroscopy of trapped ultra-cold atoms known as ”echo spectroscopy ” [M.F. Andersen et. al., Phys. Rev. Lett., in press (2002)]. Echo spectroscopy can serve as an extremely sensitive experimental tool for investigating quantum dynamics of trapped atoms even when a large number of states are thermally populated. We show numerical results for the stability of eigenstates of an atom-optics billiard of the Bunimovich type, and discuss its behavior under different types of perturbations. Finally, we propose to use special geometrical constructions to make a dephasing free dipole trap. Key words: PACS:

Chung-Yu Shih, Michael J. Gibbons, Michael Chapman

Lev Khaykovich, Nir Friedman, Roee Ozeri +2 more

Summary form only given. Utilizing cold and trapped atoms for precision spectroscopy of weak atomic transitions has two important advantages: the suppression of Doppler and time-of-flight broadenings and a combination of long interaction times, weak perturbations and tight confinement, which can be obtained using dark optical traps. We present a new and extremely sensitive method for measuring weak transitions with cold atoms in a dark optical trap, using electron shelving spectroscopy. Our scheme is based on a /spl Lambda/ system. Atoms with two ground states (for example, two hyperfine levels) are stored in the trap in a level that is coupled to the upper (excited) state, by an extremely weak transition. Atoms that undergo the weak transition may be shelved by a spontaneous Raman transition on the second ground level, which is uncoupled to the excited level by the measured photons. Finally, the detection scheme benefits from the multiply excited fluorescence of a strong closed transition from the uncoupled ground-state, that utilizes quantum amplification due to the electron shelving technique. We realized this scheme on a 5S/sub 1/2//spl rarr/5D/sub 5/2/ two-photon transition in cold and optically trapped /sup 85/Rb atoms.

Harold J. Metcalf, P. van der Straten