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

Chinese Physics Letters

Experimental Properties of Optical Phase Conjugation in Cold Atoms in a Magneto-Optical Trap

Shuyu Zhou, Tian Xia, Zhen Xu, Yuzhu Wang

Published Jan 1, 2010• 1 citation
Publisher

Abstract

We employ a sample of cold 87 Rb atoms in a magneto-optical trap to study the impulse responses and spatial characters of backward conjugate waves in a four-wave mixing process. We measure the slow and superluminal group velocities of backward conjugate waves, and find the sensitive variation of the spatial mode of backward waves with the probe-pump detuning and the dependence of the reflectance on the magnetic field, while the trapping magnetic field exists.

DOI
10.1088/0256-307x/27/1/014211

Related papers

Nonlinear spectroscopy and optical phase conjugation in cold cesium atoms

J. W. R. Tabosa, S. S. Vianna, F. A. M. de Oliveira

We have employed a sample of cold cesium atoms in a magneto-optical trap to study nonlinear spectroscopy and four-wave-mixing optical phase conjugation using a noncycling transition. Reflectivities of the order of 1% have been measured for moderate levels of pump power and large angular aperture. In particular, we have performed nonlinear spectroscopy in a three-level V-type system and observed directly the ac Stark splitting of the cesium ${6\mathrm{S}}_{1\mathrm{/}2}$, F=4 ground state.

Physical Review A•Apr 1, 1997•20 citations

Quasi-degenerate phase conjugation spectroscopy of cold cesium

George C. Cardoso, A. Lezama, J. W. R. Tabosa

Summary form only given. Resonant cold atomic samples are known to provide an efficient medium for the study of nonlinear optical processes such as four-wave-mixing (FWM) and phase conjugation (PC). Although this system is frequently modeled as an homogeneous sample of two-level atoms, the actual nonlinear response strongly depends on the internal structure (Zeeman degeneracy) of the atomic energy levels and consequently on the polarizations of the optical fields. We have studied the spectra of quasi-degenerate PC on the 6S/sub 1/2/(F=4)-6P/sub 3/2/(F=5) transition of cold Cs atoms for different optical polarizations. The atomic sample was obtained in a magneto-optical trap. The spectra where recorded within a 1 ms time interval during which the trapping light beams were blocked and the quadrupole magnetic field was turned off. We used a backwards FWM scheme with two counter-propagating pump beams and a probe beam. The PC signal propagates in opposite direction respect to the probe beam. Typical PC spectra as a function of frequency offset are shown for probe beam polarization parallel and perpendicular to pump polarization. Large differences are observed between these two cases demonstrating the crucial role of the Zeeman degeneracy on the atomic response. The experimental spectra are in good agreement with the theoretical predictions for FWM generation in degenerate two-level atoms.

Conference on Lasers and Electro-Optics•Aug 29, 2005•0 citations

Probe spectroscopy in an operating magneto-optical trap: The role of Raman transitions between discrete and continuum atomic states

Tomasz Brzozowski, Maria Brzozowska, Jerzy Zachorowski +2 more

We report on cw measurements of probe beam absorption and four-wave-mixing spectra in a $^{85}\mathrm{Rb}$ magneto-optical trap taken while the trap is in operation. The trapping beams are used as pump light. We concentrate on the central feature of the spectra at small pump-probe detuning and attribute its narrow resonant structures to the superposition of Raman transitions between light-shifted sublevels of the ground atomic state and to atomic recoil processes. These two contributions have different dependencies on trap parameters and we show that the former is inhomogeneously broadened. The strong dependence of the spectra on the probe-beam polarization indicates the existence of large optical anisotropy of the cold-atom sample, which is attributed to the recoil effects. We point out that the recoil-induced resonances can be isolated from other contributions, making pump-probe spectroscopy a highly sensitive diagnostic tool for atoms in a working magneto-optical trap.

arXiv:physics/0409009•Physical Review A•Jan 3, 2005•42 citations

Optical phase conjugation and nonlinear spectroscopy in cold cesium atoms using a noncyclic transition

J. W. R. Tabosa, S. S. Vianna, F. A. M. de Oliveira

We have employed a sample of cold cesium atoms obtained from a magneto-optical trap to study four-wave-mixing optical phase conjugation and in particular to perform nonlinear spectroscopy in a three-level, V-type system. The presence of the strongly saturating trapping beams allows us to observe directly the AC Stark splitting of the cesium 6S/sub 1/2/,F=4 ground state. To trap the cesium atoms we have used the four-beam trap configuration.

Quantum Electronics and Laser Science Conference•Jun 7, 1996•0 citations

Superluminal and slow light propagation in cold atoms

Hoonsoo Kang, Gessler Hernandez, Yifu Zhu

The group velocity of a light pulse propagating through a four-level system exhibiting electromagnetically induced transparency can be manipulated by a pump laser. The pump laser induces the large optical nonlinearities with steep normal or anomalous dispersion. We present experimental measurements that demonstrate both slow and superluminal light propagation in cold Rb atoms.

Physical Review A•Jul 7, 2004•76 citations

Experimental study of nonlinear focusing in a magneto-optical trap using a Z-scan technique

Yingxue Wang, Mark E. Saffman

We present an experimental study of $Z$-scan measurements of the nonlinear response of cold Cs atoms in a magneto-optical trap. Numerical simulations of the $Z$-scan signal accounting for the nonuniform atomic density agree with experimental results at large probe beam detunings. At small probe detunings a spatially varying radiation force modifies the $Z$-scan signal. We also show that the measured scan is sensitive to the atomic polarization distribution.

arXiv:physics/0403006•Physical Review A•Jul 1, 2004•23 citations
We employ a sample of cold 87 Rb atoms in a magneto-optical trap to study the impulse responses and spatial characters of backward conjugate waves in a four-wave mixing process. We measure the slow and superluminal group velocities of backward conjugate waves, and find the sensitive variation of the spatial mode of backward waves with the probe-pump detuning and the dependence of the reflectance on the magnetic field, while the trapping magnetic field exists.
We have employed a sample of cold cesium atoms in a magneto-optical trap to study nonlinear spectroscopy and four-wave-mixing optical phase conjugation using a noncycling transition. Reflectivities of the order of 1% have been measured for moderate levels of pump power and large angular aperture. In particular, we have performed nonlinear spectroscopy in a three-level V-type system and observed directly the ac Stark splitting of the cesium 6S1/2{6\mathrm{S}}_{1\mathrm{/}2}6S1/2​, F=4 ground state.
Summary form only given. Resonant cold atomic samples are known to provide an efficient medium for the study of nonlinear optical processes such as four-wave-mixing (FWM) and phase conjugation (PC). Although this system is frequently modeled as an homogeneous sample of two-level atoms, the actual nonlinear response strongly depends on the internal structure (Zeeman degeneracy) of the atomic energy levels and consequently on the polarizations of the optical fields. We have studied the spectra of quasi-degenerate PC on the 6S/sub 1/2/(F=4)-6P/sub 3/2/(F=5) transition of cold Cs atoms for different optical polarizations. The atomic sample was obtained in a magneto-optical trap. The spectra where recorded within a 1 ms time interval during which the trapping light beams were blocked and the quadrupole magnetic field was turned off. We used a backwards FWM scheme with two counter-propagating pump beams and a probe beam. The PC signal propagates in opposite direction respect to the probe beam. Typical PC spectra as a function of frequency offset are shown for probe beam polarization parallel and perpendicular to pump polarization. Large differences are observed between these two cases demonstrating the crucial role of the Zeeman degeneracy on the atomic response. The experimental spectra are in good agreement with the theoretical predictions for FWM generation in degenerate two-level atoms.
We report on cw measurements of probe beam absorption and four-wave-mixing spectra in a 85Rb^{85}\mathrm{Rb}85Rb magneto-optical trap taken while the trap is in operation. The trapping beams are used as pump light. We concentrate on the central feature of the spectra at small pump-probe detuning and attribute its narrow resonant structures to the superposition of Raman transitions between light-shifted sublevels of the ground atomic state and to atomic recoil processes. These two contributions have different dependencies on trap parameters and we show that the former is inhomogeneously broadened. The strong dependence of the spectra on the probe-beam polarization indicates the existence of large optical anisotropy of the cold-atom sample, which is attributed to the recoil effects. We point out that the recoil-induced resonances can be isolated from other contributions, making pump-probe spectroscopy a highly sensitive diagnostic tool for atoms in a working magneto-optical trap.
We present an experimental study of ZZZ-scan measurements of the nonlinear response of cold Cs atoms in a magneto-optical trap. Numerical simulations of the ZZZ-scan signal accounting for the nonuniform atomic density agree with experimental results at large probe beam detunings. At small probe detunings a spatially varying radiation force modifies the ZZZ-scan signal. We also show that the measured scan is sensitive to the atomic polarization distribution.