Fluorescence observation of cold atoms near the glass surface

Daniel. SahaguÌn SaÌnchez

R. J. C. Spreeuw, V. V. Ivanov, R. A. Cornelussen +1 more

Measurements of the radiative properties of cold 87 Rb atoms close to a dielectric/vacuum interface are reported. This is the first observation of a quantum-electrodynamic (QED) modification of radiative properties in vacuum near a dielectric surface. Evanescent wave (EW) spectroscopy on cold atoms that were dropped on a glass surface was used. An increase of the natural linewidth by up to 25% compared to the free space value was found. This was attributed to QED broadening and level shifts, as well as local Stark shifts near the surface. By varying the characteristic EW length, a position dependence characteristic for QED was observed. The role of transient internal dynamics of the atoms as they move through the strongly inhomogeneous EW was investigated.

M. P. A. Jones, Chris J. Vale, Daniel Sahagún +6 more

A. Anderson, S. Haroche, E. A. Hinds +3 more

We present an experimental study which shows that a large fraction (\ensuremath{\le} 50%) of thermal Cs atoms are nearly specularly reflected by polished glass surfaces at grazing incidence. This effect is interesting in the context of projects aimed at storing cold alkali-metal atoms in boxes.

V V Ivanov, R A Cornelussen, H. B. van Linden van den Heuvell +1 more

We have observed a distance-dependent absorption linewidth of cold $^{87}$Rb atoms close to a dielectric-vacuum interface. This is the first observation of modified radiative properties in vacuum near a dielectric surface. A cloud of cold atoms was created using a magneto-optical trap (MOT) and optical molasses cooling. Evanescent waves (EW) were used to observe the behavior of the atoms near the surface. We observed an increase of the absorption linewidth with up to 25% with respect to the free-space value. Approximately half the broadening can be explained by cavity-quantum electrodynamics (CQED) as an increase of the natural linewidth and inhomogeneous broadening. The remainder we attribute to local Stark shifts near the surface. By varying the characteristic EW length we have observed a distance dependence characteristic for CQED.

Deniz D. Yavuz, Nicholas Proite