Optics and Spectroscopy
The effect of electromagnetically induced transparency in a potassium nanocell
Armen D. Sargsyan, A. Amiryan, Claude Leroy, T. A. Vartanyan, David G. Sarkisyan
Abstract
The effect of electromagnetically induced transparency (EIT) has been experimentally implemented for the first time for the (4S 1/2–4P 1/2–4S 1/2) Λ-system of potassium atom levels in a nanocell with a 770-nm-thick column of atomic vapor. It is shown that, at such a small thickness of the vapor column, the EIT resonance can be observed only when the coupling-laser frequency is in exact resonance with the frequency of the corresponding atomic transition. The EIT resonance disappears even if the coupling-laser frequency differs slightly (by ~50 MHz) from that of the corresponding atomic transition, which is due to the high thermal velocity of K atoms. The EIT resonance and related velocity selective optical pumping resonances caused by optical pumping (formed by the coupling) can be simultaneously recorded because of the small (~462 MHz) hyperfine splitting of the lower 4S 1/2 level.