S. Le Boiteux

Observation of instabilities due to mirrorless four-wave mixing oscillation in sodium

Abstract We report the observation of an instability when two counter-propagating pump beams interact with sodium atoms. The instability appears as a coherent emission around the pump beams axis. This oscillation has only been observed on the self-focusing side of the resonance in agreement with theory. The characteristics of the oscillation are very different from those of the usual conical emission.

Continuous-Wave Phase-Conjugate Self-Oscillation Induced by Na-Vapour Degenerate Four-Wave Mixing with Gain

We demonstrate experimentally that phase-conjugation (PC) by resonant degenerate four-wave mixing in Na vapour can reach large efficiencies in the c.w. regime (reflectivity up to 250%). With PC reflectivity exceeding unity, a c.w. phase-conjugate laser oscillation is obtained, for the first time on a resonant gas medium. We show that large Na densities are required, as well as large frequency detunings of the intense incident beams. The PC oscillation is characterized through threshold effect, pump depletion, and polarization characteristics.

Reflection of metastable neon atoms by a surface plasmon wave

Abstract Reported is an experimental realization of an atomic mirror for a metastable neon beam whose principle is based upon the dipole force extented by a surface plasmon wave. The first experimental evidence for Doppleron resonances induced by a stationary inhomogeneous wave is demonstrated.

Atomic Interferometry with Metastable Hydrogen Atoms

An atomic interferometer using the longitudinal Stern-Gerlach effect has been constructed. A thermal beam of metastable hydrogen atoms has been used to test the apparatus. Interference patterns have been obtained. The visibility of the fringes is limited by the velocity spread of the beam. The observed patterns are in good agreement with that predicted from the actual velocity distribution.

Four-wave mixing in OH: comparison between CARS and DFWM

SummaryA comparison between CARS and Degenerate Four-Wave Mixing experiments on OH is performed in a premixed CH4-air flame. Both optical phase conjugation and forward BOXCARS geometries are studied in DFWM. The relative properties of these two configurations are experimentally investigated from the study of theP andQ branches of the (O−O) band.

Optical Stark Splitting in Doppler-Broadened, Nondegenerate Multiwave Mixing

We report on the first observation of optical Stark splitting in noncollinear, nondegenerate multiwave mixing, in Doppler-broadened gas media. We demonstrate this optical line splitting to be the dominant wave mixing process at large e.m. field intensities. Polarization characteristics of this type of high-order mixing processes are investigated, and applications to methods of optical phase conjugation with frequency up-conversion are outlined.

Doppler-free spectroscopy at a glass-vapour interface by saturated selective reflection at near normal incidence

Doppler-free spectra of gas phase atoms near a glass-vapour interface are obtained by monitoring the reflection of a probe beam-instead of its transmission-in three-level saturation spectroscopy. Experiments performed on the 3S-3P-4D cascade system of Na have allowed the authors to monitor two-photon-induced saturated dispersion of Na atoms.

Doppler-free monitoring of weak UV transitions by high frequency optical heterodyne three level spectroscopy

Abstract We propose the extension of high-frequency (HF) optical heterodyne Doppler-free spectroscopy to UV transitions, by means of combined visible-UV three-level spectroscopy. Saturation by a strong visible laser, and HF detection techniques, provide a sensitive way to probe weak transitions with low-power UV sources. This method is demonstrated here on various UV transitions in a Ne discharge.

A longitudinal stern-gerlach atomic interferometer

A new magnetic field configuration has been used in the mixing and elongating regions of the longitudinal Stern-Gerlach interferometer. This configuration has proven to considerably improve the performances of the interferometer. An analysis in terms of the vector model of a spin 1 particle is presented.

Longitudinal Stern-Gerlach atomic interferometry using velocity selected atomic beams

New experiments have been carried out on a velocity selected beam of H(D)*(2s12/) atoms using a longitudinal Stern-Gerlach atomic interferometer. A large number of fringes of the interference pattern has been observed. The results are in good agreement with theoretical predictions. An application to a topological phaseshift of the Aharonov-Anandan type is given.