Lorenzo Lenci

Vectorial atomic magnetometer based on coherent transients of laser absorption in Rb vapor

We have designed and tested an atomic vectorial magnetometer based on the analysis of the coherent oscillatory transients in the transmission of resonant laser light through a Rb vapor cell. We show that the oscillation amplitudes at the Larmor frequency and its first harmonic are related through a simple formula to the angles determining the orientation of the magnetic field vector. The magnetometer was successfully applied to the measurement of the ambient magnetic field.

Theoretical study of dark resonances in micrometric thin cells

We investigate theoretically dark resonance spectroscopy for a dilute atomic vapor confined in a thin (micrometric) cell. We identify the physical parameters characterizing the spectra and study their influence. We focus on a Hanle-type situation, with an optical irradiation under normal incidence and resonant with the atomic transition. The dark resonance spectrum is predicted to combine broad wings with a sharp maximum at line center, which can be singled out when detecting a derivative of the dark resonance spectrum. This narrow signal derivative, shown to broaden only sublinearly with the cell length, is a signature of the contribution of atoms slow enough to fly between the cell windows in a time as long as the characteristic ground state optical pumping time. We suggest that this dark resonance spectroscopy in micrometric thin cells could be a suitable tool for probing the effective velocity distribution in the thin cell arising from the atomic desorption processes, and notably to identify the limiting factors affecting desorption under a grazing incidence.

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.

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.

Sub-Doppler resonances in the backscattered light from random porous media infused with Rb vapor

We report on the observation of sub-Doppler resonances on the back-scattered light from a random porous glass medium with rubidium vapor filling its interstices. The sub-Doppler spectral lines are the consequence of saturated absorption where the incident laser beam saturates the atomic medium and the back-scattered light probes it. Some specificities of the observed spectra reflect the transient atomic evolution under confinement inside the pores. Simplicity, robustness and potential miniaturization are appealing features of this system as a spectroscopic reference.

Two-photon excitation of rubidium atoms inside porous glass

We study the two-photon laser excitation to the 5D

Nonlinear atomic spectroscopy in a random porous medium

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Raman-Ramsey Multi-zone Spectroscopy in Rb Vapor

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Atomic frequency references based on dark resonances in micrometric thin cells

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Raman-Ramsey multizone spectroscopy in a pure rubidium vapor cell

Rb atoms contained in the interstices of a porous material made from sintered ground glass with typical pore dimensions in the 10 - 100