This article is cited in
2 papers
Spectroscopy and physics of atoms and molecules
Rivalry of the dark resonance concentration narrowing and field broadening in the ladder system of rubidium atoms: thin spectroscopic cells peculiarities
A. Sargsyana,
C. S. Adamsb,
T. A. Vartanyanc,
D. Sarkisyana a Institute for Physical Research NAS of Armenia, Ashtarak, Armenia
b Joint Quantum Centre (Durham-Newcastle), Department of Physics, Durham University, Durham, UK
c St. Petersburg National Research University of Information Technologies, Mechanics and Optics
Abstract:
The effect of electromagnetically-induced transparency in the ladder system of
$5S_{1/2}-5P_{3/2}-5D_{5/2}$ levels of Rb atoms is studied. The effect of spectral narrowing of the dark resonance (DR) is shown depending on the density of atomic vapor and the thickness
$L$ of the spectroscopic cell, which contains Rb atomic vapor. The thickness
$L$ varies from 390 nm to 4 mm, the atomic density
$N$ increased to
$\sim$10
$^{16}$ cm
$^{-3}$, and intense coupling and weak probe radiation were used. The maximum effect, namely the 22-fold spectral narrowing of DR, was achieved in a cell with a thickness of
$L$ = 4 mm. With decreasing of the thickness
$L$, the effect of spectral narrowing becomes weaker: for example, at
$L$ = 2
$\mu$m, a 2.4-fold spectral narrowing of DR occurs. The spectral narrowing of DR was practically absent at
$L$ = 0.8
$\mu$m, and with a further decrease to
$L$ = 0.4
$\mu$m with increasing of atomic vapor density, spectral broadening of DR began to occur. In almost all cases, at moderate atomic densities and high intensities of the coupling radiation,
$\sim$100% DR contrast was achieved. The effect of spectral narrowing and broadening of DR is explained.
Keywords:
electromagnetically induced transparency, ladder system of levels, dark resonances, Rb atoms, Doppler broadening. Received: 03.06.2020
Revised: 03.06.2020
Accepted: 23.06.2020
DOI:
10.21883/OS.2020.10.50011.166-20