Nanocell spectroscopy interpreted in the frame of the Bloch vector model

The elementary Bloch vector model, that describes in a simple geometrical model the behaviour of a closed 2-level atom, reveals appropriate to understand the absorption behaviour, with its coherent Dicke narrowing occurring for a λ/2 thickness and with revival at (2n+1)λ/2, and the fluorescence behaviour, unsensitive to this periodical Dicke-type narrowing. This report discusses on how to understand the wash out of the sharpest features of the coherent Dicke narrowing, when relaxation or saturation are taken into account.