Laser-Experiments with Single Atoms in Cavities and Traps

HERBERT WALTHER

HERBERT WALTHER

HERBERT WALTHER

In this paper recent experiments with the one-atom maser or micromaser are described. They deal with the dynamical behavior of the field at parameter values where the field undergoes phase transitions. In the second part of the paper experiments with a single laser-cooled In+ ion in a modified Paul trap are discussed. The aim of this experiment is precision spectroscopy and cavity quantum electrodynamics on the basis of quantum jumps.

Christina J. Hood, T. W. Lynn, Andrew C. Doherty +3 more

Two recent experiments are discussed which demonstrate real-time trapping and monitoring of single atoms within a high-finesse optical resonator. A single atom moving within the resonator generates large variations in the transmission of a weak probe laser, which are recorded in real time. These cavity QED signals are used to trigger ON a confining potential to trap the atom. In the first experiment, the confining potential is provided by the single-photon forces associated with the cavity QED interaction. An inversion algorithm allows individual atom trajectories to be reconstructed from the record of cavity transmission, and reveals single atoms bound in orbit by the mechanical forces associated with single photons. In a second experiment, an additional classical standing-wave dipole trap provides the trapping, enabling a 28 ms trap lifetime for single strongly coupled atoms.

HERBERT WALTHER

In this paper, recent experiments of our group performed with single atoms in cavities and traps are summarized. In the first part, experiments with the one-atom maser are described dealing with the generation of number states of the photon field. In the second part of the paper, the spectroscopy of a single trapped In + ion is discussed being performed with the aim of realizing a new frequency standard in the optical range.

HERBERT WALTHER