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:0910.5024

Probing Zeeman coherence in nearly degenerate two-level atomic vapour with four-wave mixing

A. M. Akulshin, A. I. Sidorov, Russell McLean, Peter Hannaford

Published Oct 27, 2009• 0 citations
arXivHTMLPDF

Abstract

We present results of a study of four-wave mixing in Rb vapour with highly nonlinear susceptibility, using both homodyne and heterodyne detection. We demonstrate that the spectra have different appearances for media possessing electromagnetically induced transparency and electromagnetically induced absorption, and for different relative polarizations of the drive and probe fields. We show that these differences allow the contributions of different processes responsible for the enhanced Kerr nonlinearity of the media to be distinguished.

DOI
10.48550/arxiv.0910.5024

Related papers

Probing degenerate two-level atomic media by coherent optical heterodyning

A. M. Akulshin, Russell McLean, Andrei I. Sidorov +1 more

We analyse how light-induced coherent population oscillations and ground-state Zeeman coherence in an atomic medium with degenerate two-level transitions can modify spectra of applied cw resonant radiation at the sub-mW power level. The use of mutually coherent optical fields and heterodyne detection schemes allows spectral resolution at a kHz level, well below the laser linewidth. We find that ground-state Zeeman coherence may facilitate nonlinear wave mixing, while coherent population oscillations are responsible for phase and amplitude modulation of the applied fields. Conditions for the generation of new optical fields by nonlinear wave mixing in degenerate two-level atomic media are formulated.

arXiv:1106.0573•Journal of Physics B Atomic Molecular and Optical Physics•Aug 9, 2011•10 citations

Enhanced third-order nonlinear processes based on Raman resonance

Li-Ya Pei

We observe experimentally huge enhanced four-wave mixing based on Raman resonance in an 85Rb atomic vapor system. With the decrease of coupling field power or the increase of experimental temperature, the signal tends to be narrowed down in linewidth, and be basically the same spectrum as the stimulated Raman spectroscopy. It is found that the macroscopic polarization interference effect plays a crucial role in determining the nonlinear spectra. Further more, in the Doppler-broadened Λ-type energy level system, there is a strong relationship among electromagnetically induced transparency, four-wave mixing and stimulated Raman spectroscopy. The sharp transparent window in electromagnetically induced transparency can be interpreted as the suppression of Raman gain on the linear absorption of the probe field. However, the four-wave mixing signal is a new field generated by the atomic vapor system, and it comes from the Raman gain which is affected and modified by the absorption and dispersion of the nonlinear optical medium. It shows that in a Λ-type Doppler-broadened system, in essence, both the electromagnetically induced transparency and enhanced four-wave mixing stem from stimulated Raman scattering based on the third-order nonlinear processes, just the spectra of which are from different ways and objects of detection.

Acta Physica Sinica•Jan 1, 2020•1 citation

Highly selective four-wave mixing of low-intensity radiation in a degenerate two-level atomic system

A. M. Akulshin, S. Barreiro, A. Lezama

Quasi-degenerate four-wave mixing (FWM) of low-intensity radiation (with an intensity less than 1 mW cm -2 ) was observed for the 5 S 1/2 ( F =2)—5 P 3/2 ( F '=3) transition in an optically transparent 87 Rb vapour under conditions of electromagnetically induced absorption. The efficiency of frequency conversion was no less than 1% with respect to the intensity of pump waves. Nonlinear FWM is highly selective relative to the frequency detuning of pump waves (the FWM full width at half maximum was less than 50 kHz).

Quantum Electronics•Mar 31, 2000•16 citations

Atomic coherence induced Kerr nonlinearity enhancement in Rb vapour

Hai Wang, David J. Goorskey, Min Xiao

The Kerr nonlinear index of refraction for rubidium atoms is measured by using an optical ring cavity with and without electromagnetically induced transparency (EIT). Significant enhancement and inhibition of the Kerr nonlinear index is observed near resonance with EIT. The nonlinear index of refraction is measured as functions of probe and coupling frequency detunings, respectively, with and without the presence of EIT. A simple theoretical calculation including Doppler broadening is presented and is found to be in good qualitative agreement with the experimentally measured results.

Journal of Modern Optics•Mar 1, 2002•34 citations

Three-photon electromagnetically induced absorption and transparency in an inhomogeneously broadened atomic vapour

C. Y. Ye, Alexander S. Zibrov, Yuri V. Rostovtsev +2 more

We study both theoretically and experimentally three-photon electromagnetically induced transparency and electromagnetically induced absorption resonances in inhomogeneously broadened 85 Rb atomic vapour driven by probe and drive laser radiations. We observe narrow Doppler-free absorption as well as transmission resonances for the probe field when the driving laser field is redshifted from the D1 or D2 lines of 85Rb; the frequency difference between the drive and probe fields is equal to the hyperfine splitting of the ground state of the atoms, and the probe field is tuned to the centre of the Doppler broadened atomic transition. We theoretically study the spectroscopic effect in both homogeneously and inhomogeneously broadened media. Our numerical simulations are in good agreement with the experimental results.

Journal of Modern Optics•Nov 1, 2002•14 citations

Enhanced atomic Kerr nonlinearity inbrightcoherent states

A. M. Akulshin, A I Sidorov, Russell McLean +1 more

We show that long-lived bright Zeeman coherence that is responsible for absorption enhancement and steep anomalous dispersion in an atomic medium gives rise to a giant nonlinearity of the atomic susceptibility, in a similar manner to the dark coherence responsible for the well-known electromagnetically induced transparency. The intensity dependent refractive index of Cs vapour with a ground state Zeeman coherence in the vicinity of the D2 resonance line has been measured at low light intensity. The Kerr nonlinearity in the bright coherent state (n2 approx 1.0 × 10-6 cm2 mW-1) is higher than that in a dark state under the same experimental conditions. Higher order nonlinear components of the refractive index have also been estimated for both coherent states.

Journal of Optics B Quantum and Semiclassical Optics•Oct 16, 2004•26 citations
We present results of a study of four-wave mixing in Rb vapour with highly nonlinear susceptibility, using both homodyne and heterodyne detection. We demonstrate that the spectra have different appearances for media possessing electromagnetically induced transparency and electromagnetically induced absorption, and for different relative polarizations of the drive and probe fields. We show that these differences allow the contributions of different processes responsible for the enhanced Kerr nonlinearity of the media to be distinguished.
We analyse how light-induced coherent population oscillations and ground-state Zeeman coherence in an atomic medium with degenerate two-level transitions can modify spectra of applied cw resonant radiation at the sub-mW power level. The use of mutually coherent optical fields and heterodyne detection schemes allows spectral resolution at a kHz level, well below the laser linewidth. We find that ground-state Zeeman coherence may facilitate nonlinear wave mixing, while coherent population oscillations are responsible for phase and amplitude modulation of the applied fields. Conditions for the generation of new optical fields by nonlinear wave mixing in degenerate two-level atomic media are formulated.
We observe experimentally huge enhanced four-wave mixing based on Raman resonance in an 85Rb atomic vapor system. With the decrease of coupling field power or the increase of experimental temperature, the signal tends to be narrowed down in linewidth, and be basically the same spectrum as the stimulated Raman spectroscopy. It is found that the macroscopic polarization interference effect plays a crucial role in determining the nonlinear spectra. Further more, in the Doppler-broadened Λ-type energy level system, there is a strong relationship among electromagnetically induced transparency, four-wave mixing and stimulated Raman spectroscopy. The sharp transparent window in electromagnetically induced transparency can be interpreted as the suppression of Raman gain on the linear absorption of the probe field. However, the four-wave mixing signal is a new field generated by the atomic vapor system, and it comes from the Raman gain which is affected and modified by the absorption and dispersion of the nonlinear optical medium. It shows that in a Λ-type Doppler-broadened system, in essence, both the electromagnetically induced transparency and enhanced four-wave mixing stem from stimulated Raman scattering based on the third-order nonlinear processes, just the spectra of which are from different ways and objects of detection.
Quasi-degenerate four-wave mixing (FWM) of low-intensity radiation (with an intensity less than 1 mW cm -2 ) was observed for the 5 S 1/2 ( F =2)—5 P 3/2 ( F '=3) transition in an optically transparent 87 Rb vapour under conditions of electromagnetically induced absorption. The efficiency of frequency conversion was no less than 1% with respect to the intensity of pump waves. Nonlinear FWM is highly selective relative to the frequency detuning of pump waves (the FWM full width at half maximum was less than 50 kHz).
The Kerr nonlinear index of refraction for rubidium atoms is measured by using an optical ring cavity with and without electromagnetically induced transparency (EIT). Significant enhancement and inhibition of the Kerr nonlinear index is observed near resonance with EIT. The nonlinear index of refraction is measured as functions of probe and coupling frequency detunings, respectively, with and without the presence of EIT. A simple theoretical calculation including Doppler broadening is presented and is found to be in good qualitative agreement with the experimentally measured results.
We study both theoretically and experimentally three-photon electromagnetically induced transparency and electromagnetically induced absorption resonances in inhomogeneously broadened 85 Rb atomic vapour driven by probe and drive laser radiations. We observe narrow Doppler-free absorption as well as transmission resonances for the probe field when the driving laser field is redshifted from the D1 or D2 lines of 85Rb; the frequency difference between the drive and probe fields is equal to the hyperfine splitting of the ground state of the atoms, and the probe field is tuned to the centre of the Doppler broadened atomic transition. We theoretically study the spectroscopic effect in both homogeneously and inhomogeneously broadened media. Our numerical simulations are in good agreement with the experimental results.
We show that long-lived bright Zeeman coherence that is responsible for absorption enhancement and steep anomalous dispersion in an atomic medium gives rise to a giant nonlinearity of the atomic susceptibility, in a similar manner to the dark coherence responsible for the well-known electromagnetically induced transparency. The intensity dependent refractive index of Cs vapour with a ground state Zeeman coherence in the vicinity of the D2 resonance line has been measured at low light intensity. The Kerr nonlinearity in the bright coherent state (n2 approx 1.0 × 10-6 cm2 mW-1) is higher than that in a dark state under the same experimental conditions. Higher order nonlinear components of the refractive index have also been estimated for both coherent states.