P. Verkerk

Saturation in degenerate four wave mixing: The dressed-atom approach

Abstract A dressed atom approach of saturation in degenerate four-wave mixing is presented. Because of the Doppler-shift of the pump and probes waves frequencies, a resonance between levels of the dressed atom occurs for two velocity groups. When the Rabi frequency Ω 1 is smaller than the Doppler width ku , these resonant terms give the essential contribution to the signal which is analytically calculated. When Ω 1 a ku , the signal is expected to be much smaller.

Amplified reflection in degenerate four-wave mixing: a more-accurate theory

We report a theory of amplified reflection in degenerate four-wave mixing that includes Gaussian distribution of intensity in the incoming beams and different intensities for the two pumping beams. In the Kerr limit, we obtain an analytical solution that may explain previous experimental observations.

Observation of self-oscillation in ring cavities with sodium vapor phase conjugate mirrors

Abstract We present two kinds of ring cavities with phase conjugate mirrors. One cavity requires a tuning condition while the other one can oscillate independently of the cavity length. Both cavities have been experimentally studied using a sodium vapor phase conjugate mirror. Oscillations occur without any other gain medium inside the cavity. A strong correlation between the beams propagating in opposite directions in the cavity is observed.

Level-crossing spectroscopy of atoms dressed by optical photons in degenerate four-wave mixing.

We investigate degenerate four-wave mixing on the 607.4-nm line of neon using crossed-polarized beams. We show that the line shape changes dramatically in the presence of a magnetic field. Narrow resonances are observed, which are interpreted as level-crossing resonances in the energy diagram of the dressed atom.

Cesium atoms in grey optical lattices. Study of temperature and capture efficiency

Abstract We study the three dimensional cooling of cesium atoms using a four-beam optical lattice induced by a magnetic field. The lattice beams are tuned to the blue side of the Fg = 3 → Fe = 2 hyperfine component of the 6 S 1 2 → 6 P 3 2 transition. The atomic kinetic temperature and capture efficiency are measured as a function of the magnetic field. It is shown that optimum cooling and capture efficiency are obtained when the Zeeman splitting is either much smaller or much larger than the light-shift.

Collision-aided self-focusing and self-defocusing in sodium vapor

Abstract We show that the shape of a nearly resonant cw laser beam transmitted through a sodium cell is modified when a buffer gas is introduced in the cell. Depending on the sign of the detuning from the resonance, we observe a pressure-induced self-focusing or a pressure-induced self-defocusing.

Doppler-free spectroscopy of neon atoms dressed by optical photons in nearly-degenerate four-wave mixing

Abstract We have investigated nearly degenerate four-wave mixing in neon on the 607 nm line. We have considered the case where one pump beam saturates the medium while the two other incident beams have a much weaker intensity. The frequency of the most intense pump beam is equal to the frequency of the probe beam. When the frequency of the second pump beam is scanned, narrow resonances are observed. These resonances correspond to transitions between the energy levels of the atom dressed by the photons of the intense pump beam.

Recoil-induced resonances of cesium atoms in the transient domain

Abstract We present an experimental and theoretical study of the recoil-induced resonances in the transiers domain. We describe the time dependence of the atomic bunching in the optical potential. We show that the usual line shape which is proportional to the derivative of the velocity distribution is only correct after some delay.