Formation of narrow optical resonance by micrometer thin Rb-vapor layer

Abstract

Recently developed thin cells containing atomic vapor of micrometric column thickness L allow one to study peculiarities of Electromagnetically Induced Transparency (EIT) phenomenon, along with the accompanying velocity selective optical pumping/saturation (VSOP) resonances for the case when < 100 μm. The micrometric thin cells (MTC) are filled with pure Rb and neither buffer gas nor paraffin-coated walls were used. The A-systems on D 2 line of 85 Rb have been studied experimentally with the use of bi-chromatic radiation of two separate diode lasers (λ ≃780 nm, γ L ≃ 5MHz). It is demonstrated that when L∼60 μm it is still possible to form the EIT resonance with the sub-natural linewidth ∼ 5 MHz. The EIT resonance linewidth increases up to 10 MHz, when column thickness L is reduced down to Dependence of the EIT resonances are detected in the fluorescence and absorption spectra when the thickness L ∼ 10 μm. Dependence of the EIT resonance linewidth as a function of the atomic vapor column thickness L is presented.