Article

Electromagnetically induced transparency: the thickness of the vapor column is of the order of a light wavelength

University of Burgundy, Dijon, Bourgogne, France
Journal of the Optical Society of America B (Impact Factor: 1.81). 08/2007; 24(8):1829-1838. DOI: 10.1364/JOSAB.24.001829

ABSTRACT Electromagnetically induced transparency (EIT) effect has been studied using an extremely thin cell (ETC) with the thickness of an Rb vapor column of the order of light wavelength λ(780nm) and varying in the range of 0.5λ–2.5λ . Λ-systems on the D2 line of Rb85 and Rb87 have been studied experimentally. Along with EIT resonance, we study the peculiarities of velocity-selective optical pumping/saturation (VSOP) resonances, which accompany the EIT resonance and, as a rule, are spectrally broader. It is demonstrated that size-conditioned strongly anisotropic contribution of atoms with different velocities in an ETC causes several dramatic differences of the EIT and VSOP resonances formation in the ETC as compared with an ordinary 1–10cm long cell. Particularly, in the case of the ETC, the EIT linewidth and contrast dramatically depend on the coupling laser detuning from the exact atomic transition. A theoretical model taking into account the peculiarities of transmission spectra when L=nλ and L=(2n+1)λ/2 (n is an integer) has been developed. The experimental transmission spectra are well described by the theoretical model developed. The possibility of EIT resonance formation when atomic column thickness is of the order of L=0.5λ and less is theoretically predicted

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