Rb optical resonance inside a random porous medium.

We studied resonant laser interaction with Rb atoms confined to the interstitial cavities of a random porous glass. Due to diffusive light propagation, the effect of atomic absorption on the light scattered by the sample is almost entirely compensated by atomic fluorescence at low atomic densities. For higher densities, radiation trapping increases the probability of nonradiative decay via atom-wall collisions. A simple connection of the fluorescence/absorption yield to the sample porosity is given.

Dark resonances in thin cells for miniaturized atomic-frequency references.

We present theoretical arguments and experimental data in support of the use of thin alkaline-atom vapor cells, without buffer gas, for the realization of miniaturized (submillimetric) atomic frequency references.

Simultaneous micromechanical and electromagnetic detection of electron paramagnetic resonance

The peculiar advantages of simultaneous observation by electromagnetic and micromechanical methods in EPR spectroscopy are discussed. The development of a novel apparatus with the capability of this simultaneous detection is described. Experiments at 23 GHz show the performance of the apparatus. The problems related to the sensitivity and to the spatial resolution are analyzed. Future prospects are presented. Copyright 1999 Academic Press.