Atomic four-levelNsystems

Abstract

We investigate the atomic four-level N configuration both analytically and numerically, for various pump and probe intensities, with and without transfer of coherence (TOC) and Doppler broadening, and compare the results obtained to those of realistic atomic systems. We find that TOC affects the whole spectrum, in addition to producing an electromagnetically induced absorption (EIA) peak at line center. We show that the EIA peak splits as the pump intensity increases. These results are compared with those of realistic systems. When the pump is + polarized and the probe is polarized, the results are similar to those of the N configuration. When the pump and probe polarizations are both linear with perpendicular polarizations, various N-like subsystems contribute to the spectrum. Consequently, the splitting of the EIA peak only occurs at very high pump intensities. We also discuss the influence of the probe on the pump absorption and refraction and find that both the pump and probe show EIA peaks when the pump intensity is low, and complementary behavior when the pump is intense. At both low and high pump intensity, the pump and probe dispersions are of opposite sign.

Optomechanical analog of two-color electromagnetically induced transparency: Photon transmission through an optomechanical device with a two-level system

“…This is because the Jaynes-Cummings coupling between the two-level system and the mechanical resonator can lead to dressed states, which have a more complicated energy structure. This usually leads to a more complicated absorption of a weak probe field by a hybrid system, and can be referred to as an EIT in a multi-level atom system [88][89][90].…”

High-efficiency four-wave mixing in a five-level atomic system based on two-electromagnetically induced transparency in the ultraslow propagation regime

“…The reason for the above result can be qualitatively explained as follows. Our atomic system is a kind of atomic configuration which owns the property of the double-dark resonances [21,22]. Under this condition, the coherent interaction for this atomic system can lead to the emergence of sharp spectral features of interacting double-dark resonances which strongly modify the optical properties of the double EIT windows.…”

Coherent processes in electromagnetically induced absorption: a steady and transient study

“…Using an N -configuration atom, Taichenachev et al [12] have shown that the sign of the absorption resonance can change, depending on the rate of coherence transfer, and that EIA can turn into enhanced transmission in the case of zero or even a low rate of coherence transfer. EIA in an N -type interaction scheme has also been investigated for various pump and probe intensities with and without transfer of coherence and Doppler broadening in [13], both analytically and numerically. The results were compared with the results obtained for realistic atomic systems.…”

“…In [12], the role of the ground-state Zeeman coherence, transfer to the excited-state coherence was not discussed. In [13], it was shown that the transfer of coherences can affect the whole spectrum, not only the EIA peak. The spontaneous transfer of Zeeman coherences from the excited to ground levels influences, as shown in [11], the nonlinear resonances in probe-field spectroscopy.…”

“…The spontaneous transfer of Zeeman coherences from the excited to ground levels influences, as shown in [11], the nonlinear resonances in probe-field spectroscopy. The transfer of coherences can be neglected [29] if excited states are far apart in energy.…”