Electromanetically Induced Resonances in Sub-Micron Thin Rb-Vapor Layer

David G. Sarkisyan, Armen D. Sargsyan, A. Papoyan +2 more

Armen D. Sargsyan, David G. Sarkisyan

Armen D. Sargsyan, Anahit L. Gogyan, David G. Sarkisyan

Armen D. Sargsyan

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 &mgr;m. The micrometric thin cells (MTC) are filled with pure Rb and neither buffer gas nor paraffin-coated walls were used. The Λ-systems on D2 line of 85Rb have been studied experimentally with the use of bi-chromatic radiation of two separate diode lasers (λ≈780 nm, γL&≈ 5MHz). It is demonstrated that when L~60 &mgr;m 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 ~ 2 &mgr;m. Six VSOP resonances are detected in the fluorescence and absorption spectra when the thickness L ~ 10 &mgr;m. Dependence of the EIT resonance linewidth as a function of the atomic vapor column thickness L is presented.

M. E. Movsesyan, N. N. Badalyan, V. A. Iradyan

David G. Sarkisyan, A. Papoyan, T. Varzhapetyan +3 more

We report the first use of an extremely thin vapor cell (thickness ~ 400 nm) to study the magnetic-field dependence of laser-induced-fluorescence excitation spectra of alkali atoms. This thin cell allows for sub-Doppler resolution without the complexity of atomic beam or laser cooling techniques. This technique is used to study the laser-induced-fluorescence excitation spectra of Rb in a 50 G magnetic field. At this field strength the electronic angular momentum J and nuclear angular momentum I are only partially decoupled. As a result of the mixing of wavefunctions of different hyperfine states, we observe a nonlinear Zeeman effect for each sublevel, a substantial modification of the transition probabilities between different magnetic sublevels, and the appearance of transitions that are strictly forbidden in the absence of the magnetic field. For the case of right- and left- handed circularly polarized laser excitation, the fluorescence spectra differs qualitatively. Well pronounced magnetic field induced circular dichroism is observed. These observations are explained with a standard approach that describes the partial decoupling of I and J states.