Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:quant-ph/0309151 · Journal of the Optical Society of America B

Absorption resonance and large negative delay in rubidium vapor with a buffer gas

Eugeniy E. Mikhailov, Vladimir A. Sautenkov, Yuri V. Rostovtsev, George R. Welch

Published Feb 1, 2004• 67 citations
arXivHTMLPDF

Abstract

We observe a narrow, isolated, two-photon absorption resonance in 87Rb for large one-photon detuning in the presence of a buffer gas. In the absence of a buffer gas, a standard Λ configuration of two laser frequencies gives rise to electromagnetically induced transparency (EIT) for all values of one-photon detuning throughout the inhomogeneously (Doppler) broadened line. However, when a buffer gas is added and the one-photon detuning is comparable to or greater than the Doppler width, an absorption resonance appears instead of the usual EIT resonance. We also observe a large negative group delay (≈−300 μs for a Gaussian pulse that propagates through the media with respect to a reference pulse not affected by the media), corresponding to a superluminal group velocity vg=−c/(3.6×106)=−84 m/s.

DOI
10.1364/josab.21.000425

Related papers

Buffer-gas-induced absorption resonances in Rb vapor

Eugeniy E. Mikhailov, Irina V. Novikova, Yuri V. Rostovtsev +1 more

We observe transformation of the electromagnetically induced transparency (EIT) resonance into an absorption resonance in a $\ensuremath{\Lambda}$ interaction configuration in a cell filled with $^{87}\mathrm{Rb}$ and a buffer gas. This transformation occurs as one-photon detuning of the coupling fields is varied from the atomic transition. No such absorption resonance is found in the absence of a buffer gas. The width of the absorption resonance is several times smaller than the width of the EIT resonance, and the changes of absorption near these resonances are about the same. Similar absorption resonances are detected in the Hanle configuration in a buffered cell.

arXiv:quant-ph/0309171•Physical Review A•Sep 20, 2004•46 citations

Large negative and positive delay of optical pulses in coherently prepared dense Rb vapor with buffer gas

Eugeniy E. Mikhailov, Vladimir A. Sautenkov, Irina V. Novikova +1 more

We experimentally study the group time delay for a light pulse propagating through hot $^{87}\mathrm{Rb}$ vapor in the presence of a strong coupling field in a $\ensuremath{\Lambda}$ configuration. We demonstrate that the ultraslow pulse propagation is transformed into superluminal propagation as the one-photon detuning of the light increases due to the change in the transmission resonance line shape. Negative group velocity as low as $\ensuremath{-}c∕{10}^{6}=\ensuremath{-}80\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s}$ is recorded. We also find that the advance time in the regime of the superluminal propagation grows linearly with increasing laser field power.

arXiv:quant-ph/0402120•Physical Review A•Jun 14, 2004•66 citations

Group velocity study in hot 87 Rb vapour with buffer gas

George R. Welch, Eugeniy E. Mikhailov, Yuri V. Rostovtsev

We study the behavior of the group velocity of light under conditions of electromagnetically induced transparency (EIT) in a Doppler broadened medium. Specifically, we show how the group delay (or group velocity) of probe and generated Stokes fields depends on the one-photon detuning of drive and probe fields. We find that for atoms in a buffer gas the group velocity decreases with positive one-photon detuning of the drive fields, and increases when the fields are red detuned. This dependence is counter-intuitive to what would be expected if the one-photon detuning resulted in an interaction of the light with the resonant velocity subgroup.

arXiv:quant-ph/0309173•Journal of Modern Optics•Jan 1, 2003•0 citations

Group velocity study in hot87Rb vapour with buffer gas

Eugeniy E. Mikhailov, Yuri V. Rostovtsev, George R. Welch

We study the behaviour of the group velocity of light under conditions of electromagnetically induced transparency (EIT) in a Doppler broadened medium. Specifically, we show how the group delay (or group velocity) of probe and generated Stokes fields depends on the one-photon detuning of drive and probe fields. We find that for atoms in a buffer gas the group velocity decreases with positive one-photon detuning of the drive fields, and increases when the fields are red detuned. This dependence is counterintuitive to what would be expected if the one-photon detuning resulted in an interaction of the light with the resonant velocity subgroup.

Journal of Modern Optics•Oct 1, 2003•27 citations

Electromagnetically induced transparency of 87 Rb in a buffer gas cell with magnetic field

Hong Cheng, Han-Mu Wang, Shanshan Zhang +3 more

Abstract We have studied the phenomenon of electromagnetically induced transparency (EIT) of 87 Rb vapor at room temperature in a magnetic field with an arbitrary angle to the laser propagation direction. Rather than exposing atoms to a parallelled or transverse magnetic field as usual, in our work, we apply a magnetic field (up to 45 Gauss) with an arbitrary angle to the laser propagation direction and the spectra become much more complex. More EIT dips are observed due to the Zeeman splitting on the D 2 line of 87 Rb in a Λ -type configuration. With a 5 Torr N 2 buffer gas in the thermal 2 cm vapor cell, the state 5 2 P 3 / 2 has a very short effective lifetime, corresponding to a large energy broadening, which removes the velocity selective optical pumping effect almost completely and keeps the high resolution EIT spectrum for the energy splitting of 87 Rb in magnetic fields. The shifting of the EIT resonances with the strength of the applied magnetic field coincides well with the theory based on a full matrix Hamiltonian combined with a spectral decomposition method. Our work can be extended to measure the magnetic field vector in space. The effects of the detuning of the probe and coupling beams on the spectral lines are also investigated.

Journal of Physics B Atomic Molecular and Optical Physics•Apr 18, 2017•35 citations

Velocity selective multiple two-photon dark and bright resonances in Potassium vapor

Gourab Pal, Subhasish Dutta Gupta, Saptarishi Chaudhuri

Abstract We report the observation of two additional sub-natural line width quantum interferences in the D 2 manifold of 39 K vapor, in addition to the usual single Electromagnetically Induced Transparency (EIT) peak. In a typical three level Λ-type system, only one EIT peak is observed. However, here we report observation of two additional line shapes riding on top of the absorption profile. The fact that the hyperfine splitting is smaller than the Doppler width in 39 K allows the probe and control beams to swap their transition pathways in different velocity groups of atoms even when their frequencies are kept constant. Our observations are in striking contrast to standard EIT measurements. These findings are in quantitative agreement with density matrix formalism taking into account velocity-selective two-photon resonances. Owing to the favorably low ground hyperfine splitting (Δ hf ) in 39 K, which allows a significantly large number of atoms with a Doppler shift greater than or equal to the Δ hf , the strength of these additional resonances is strong compared to that of other alkali atoms such as 87 Rb, 133 Cs where these resonances can not be observed. The control photon detuning to atomic transition captures the nature of the coherence; therefore an unusual phenomenon of conversion from perfect transparency to enhanced absorption of the probe photon is observed and explained by utilizing the adiabatic elimination of the excited state in the Master equation. Controlling such dark and bright resonances leads to new applications in quantum technologies such as frequency-offset laser stabilization and long-lived quantum memory.

Physica Scripta•Jun 24, 2024•0 citations
We observe a narrow, isolated, two-photon absorption resonance in 87Rb for large one-photon detuning in the presence of a buffer gas. In the absence of a buffer gas, a standard Λ configuration of two laser frequencies gives rise to electromagnetically induced transparency (EIT) for all values of one-photon detuning throughout the inhomogeneously (Doppler) broadened line. However, when a buffer gas is added and the one-photon detuning is comparable to or greater than the Doppler width, an absorption resonance appears instead of the usual EIT resonance. We also observe a large negative group delay (≈−300 μs for a Gaussian pulse that propagates through the media with respect to a reference pulse not affected by the media), corresponding to a superluminal group velocity vg=−c/(3.6×106)=−84 m/s.
We observe transformation of the electromagnetically induced transparency (EIT) resonance into an absorption resonance in a $\ensuremath{\Lambda}$ interaction configuration in a cell filled with 87Rb^{87}\mathrm{Rb}87Rb and a buffer gas. This transformation occurs as one-photon detuning of the coupling fields is varied from the atomic transition. No such absorption resonance is found in the absence of a buffer gas. The width of the absorption resonance is several times smaller than the width of the EIT resonance, and the changes of absorption near these resonances are about the same. Similar absorption resonances are detected in the Hanle configuration in a buffered cell.
We experimentally study the group time delay for a light pulse propagating through hot 87Rb^{87}\mathrm{Rb}87Rb vapor in the presence of a strong coupling field in a $\ensuremath{\Lambda}$ configuration. We demonstrate that the ultraslow pulse propagation is transformed into superluminal propagation as the one-photon detuning of the light increases due to the change in the transmission resonance line shape. Negative group velocity as low as $\ensuremath{-}c∕{10}^{6}=\ensuremath{-}80\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s}$ is recorded. We also find that the advance time in the regime of the superluminal propagation grows linearly with increasing laser field power.
We study the behavior of the group velocity of light under conditions of electromagnetically induced transparency (EIT) in a Doppler broadened medium. Specifically, we show how the group delay (or group velocity) of probe and generated Stokes fields depends on the one-photon detuning of drive and probe fields. We find that for atoms in a buffer gas the group velocity decreases with positive one-photon detuning of the drive fields, and increases when the fields are red detuned. This dependence is counter-intuitive to what would be expected if the one-photon detuning resulted in an interaction of the light with the resonant velocity subgroup.
We study the behaviour of the group velocity of light under conditions of electromagnetically induced transparency (EIT) in a Doppler broadened medium. Specifically, we show how the group delay (or group velocity) of probe and generated Stokes fields depends on the one-photon detuning of drive and probe fields. We find that for atoms in a buffer gas the group velocity decreases with positive one-photon detuning of the drive fields, and increases when the fields are red detuned. This dependence is counterintuitive to what would be expected if the one-photon detuning resulted in an interaction of the light with the resonant velocity subgroup.
Abstract We have studied the phenomenon of electromagnetically induced transparency (EIT) of 87 Rb vapor at room temperature in a magnetic field with an arbitrary angle to the laser propagation direction. Rather than exposing atoms to a parallelled or transverse magnetic field as usual, in our work, we apply a magnetic field (up to 45 Gauss) with an arbitrary angle to the laser propagation direction and the spectra become much more complex. More EIT dips are observed due to the Zeeman splitting on the D 2 line of 87 Rb in a Λ -type configuration. With a 5 Torr N 2 buffer gas in the thermal 2 cm vapor cell, the state 5 2 P 3 / 2 has a very short effective lifetime, corresponding to a large energy broadening, which removes the velocity selective optical pumping effect almost completely and keeps the high resolution EIT spectrum for the energy splitting of 87 Rb in magnetic fields. The shifting of the EIT resonances with the strength of the applied magnetic field coincides well with the theory based on a full matrix Hamiltonian combined with a spectral decomposition method. Our work can be extended to measure the magnetic field vector in space. The effects of the detuning of the probe and coupling beams on the spectral lines are also investigated.
Abstract We report the observation of two additional sub-natural line width quantum interferences in the D 2 manifold of 39 K vapor, in addition to the usual single Electromagnetically Induced Transparency (EIT) peak. In a typical three level Λ-type system, only one EIT peak is observed. However, here we report observation of two additional line shapes riding on top of the absorption profile. The fact that the hyperfine splitting is smaller than the Doppler width in 39 K allows the probe and control beams to swap their transition pathways in different velocity groups of atoms even when their frequencies are kept constant. Our observations are in striking contrast to standard EIT measurements. These findings are in quantitative agreement with density matrix formalism taking into account velocity-selective two-photon resonances. Owing to the favorably low ground hyperfine splitting (Δ hf ) in 39 K, which allows a significantly large number of atoms with a Doppler shift greater than or equal to the Δ hf , the strength of these additional resonances is strong compared to that of other alkali atoms such as 87 Rb, 133 Cs where these resonances can not be observed. The control photon detuning to atomic transition captures the nature of the coherence; therefore an unusual phenomenon of conversion from perfect transparency to enhanced absorption of the probe photon is observed and explained by utilizing the adiabatic elimination of the excited state in the Master equation. Controlling such dark and bright resonances leads to new applications in quantum technologies such as frequency-offset laser stabilization and long-lived quantum memory.