arXiv subjects
Publications and source records attributed to S. Reynaud.
We study the generation of photon pulses from thermal field fluctuations through opto-mechanical coupling to a cavity with an oscillatory motion. Pulses are regularly spaced and become sharp for a high finesse cavity.
We evaluate the squeezing of a probe beam with a transverse Gaussian profile interacting with an ensemble of two-level atoms in a cavity. We use the linear input-output formalism where the effect of atoms is described by susceptibility and noise functions. The transverse structure is accounted for by averaging atomic functions over the intensity profile. The results of the plane-wave and Gaussian-wave theories are compared. When large squeezing is predicted we find the prediction of the plane-wave model not to be reliable outside the Kerr domain. We give an estimate of the squeezing degradation due to the Gaussian transverse structure.
Laser-cooled and trapped cesium atoms have been used as a nonlinear medium in a nearly resonant cavity. A study of the semiclassical dynamics of the system was performed, showing bistability and instabilities. In the quantum domain, squeezing in a probe beam having interacted with this system was demonstrated.
We show that the Casimir force between mirrors with arbitrary frequency dependent reflectivities obeys bounds due to causality and passivity properties. The force is always smaller than the Casimir force between two perfectly reflecting mirrors. For narrow-band mirrors in particular, the force is found to decrease with the mirrors bandwidth.
We evaluate the effective number of atoms in experiments where a probe laser beam with a Gaussian profile passes through an atomic medium consisting of a cold atom cloud released from a magneto-optical trap. Considering the case where the initial distribution is a Gaussian function of position and velocity, we give a quantitative description of the time variation of the effective atom number while the cloud is exploding and falling. We discuss the two cases where the effective number is defined from the linear and nonlinear phase shifts, respectively. We also evaluate the fluctuations of the effective atom number by calculating their correlation functions and the associated noise spectra. Finally we estimate the effect of these fluctuations on experiments where the probe beam passes through a cavity containing the atomic cloud.