We have investigated electromagnetically induced transparency in the spectrum of selective reflection at the interface of Rb atom vapors and a dielectric nanocell window. A nanocell with atomic vapor column thicknesses ranging from 150 to 1200 nm, as well as a 50~
μm thickness microcell were used. We have compared electromagnetically induced transparency observed for the cases of the selective reflection and transmission. It was demonstrated that for the thicknesses of below
≤1000 nm selective reflection technique is more favorable. In contrast, for wider cells and microcells, using transmitted radiation as probe field is more effective.
Electromagnetically induced transparency (EIT) resonance, along with peculiarities of the accompanying velocity selective optical pumping/saturation (VSOP) resonances, have been studied using a thin cell with the thickness of Rb vapor column varying in L = 10-700 &mgr;m range, as well as using an extremely thin cell (ETC) with the thickness varying in the range of radiation wavelength &lgr; = 780 nm (L = 0.5&lgr; - 2.5&lgr;). The &Lgr;-systems on D2 line of 85Rb and 87Rb have been studied experimentally with the use of bichromatic radiation of two separate diode lasers. It is demonstrated that size-conditioned strongly anisotropic contribution of atoms with different velocities in ETC results in several dramatic distinctions in formation of EIT and VSOP resonances in ETC, as compared with ordinary cm-size cell. The boundary between these two regimes falls on L ~ 10 &mgr;m. Theoretical model taking into account the peculiarities of the transmission spectra as a function of the ratio L/&lgr; is developed. The experimental transmission spectra are well described by the theoretical model.