Eur. Phys. J. D 30, 265-273 (2004)
https://doi.org/10.1140/epjd/e2004-00088-0

New feature in selective reflection with a highly parallel window: phase-tunable homodyne detection of the radiated atomic field

¹ Institute for Physical Research, NAS of Armenia, Ashtarak-2, 378410 Armenia
² Laboratoire Kastler Brossel ( Laboratoire de l'Université Pierre et Marie Curie et de l'ENS, associé au CNRS (UMR 8552).) et Fédération de Recherche (Fédération de Recherche de l'ENS, associée au CNRS (FR684).) , Département de Physique de l'École Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France

Corresponding author: ^a guena@lkb.ens.fr

Received: 31 March 2004
Published online: 6 July 2004

Abstract

Selective reflection (SR) of light from a cesium vapor-sapphire interface close to the D₂ resonance line has been studied by use of a sapphire window with highly parallel surfaces. Temperature-tuning of the Fabry-Perot behaviour of the window [Jahier et al., Appl. Phys. B 71, 561 (2000)], resulting in a change of 0.5 to 26% of the window reflection coefficient, dramatically affects both the magnitude and lineshape of the SR resonant atomic signal. For nearly zero window reflection, the case of particular interest, the absorptive properties of the atomic medium govern the signal shape, as opposed to the usual dispersive ones in the “ordinary” SR. This is a manifestation of homodyne detection of the radiated atomic field. The numerical simulation based on a model, which accounts for all the processes involved, shows a good agreement with the experimental spectra. Possible applications for laser and atomic spectroscopy, in particular tunable locking of laser frequency, are discussed.