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Title: Two-photon resonant four-wave mixing in a dressed atomic system: Polarization interference in a Doppler-broadened system

Abstract

We study dressed-atom two-photon resonant nondegenerate four-wave mixing (NFWM) in a Doppler-broadened system. It is found that there exists interference between the macroscopic field polarizations from different ensembles of atoms within the atomic velocity distribution. This polarization interference can cause significant modification of the NFWM spectra. We also show that two-photon resonant NFWM in dressed atoms can be employed as a new type of Doppler-free high-resolution Autler-Townes spectroscopy for measuring transition dipole moments between two highly excited atomic states.

Authors:
; ; ;  [1];  [2]
  1. Laboratory of Optical Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China)
  2. Department of Physics, Hebei University, Hebei, 071002 (China)
Publication Date:
OSTI Identifier:
20982181
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevA.75.023805; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ATOMS; DIPOLE MOMENTS; DISTRIBUTION; DOPPLER BROADENING; EXCITED STATES; FREQUENCY MIXING; INTERFERENCE; MIXING; MODIFICATIONS; MULTI-PHOTON PROCESSES; OPTICS; PHOTON-ATOM COLLISIONS; PHOTONS; POLARIZATION; RESOLUTION; SPECTRA; SPECTROSCOPY

Citation Formats

Zuo, Zhanchun, Liu, Xia, Wu, Ling-An, Fu, Panming, and Sun, Jiang. Two-photon resonant four-wave mixing in a dressed atomic system: Polarization interference in a Doppler-broadened system. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.023805.
Zuo, Zhanchun, Liu, Xia, Wu, Ling-An, Fu, Panming, & Sun, Jiang. Two-photon resonant four-wave mixing in a dressed atomic system: Polarization interference in a Doppler-broadened system. United States. doi:10.1103/PHYSREVA.75.023805.
Zuo, Zhanchun, Liu, Xia, Wu, Ling-An, Fu, Panming, and Sun, Jiang. Thu . "Two-photon resonant four-wave mixing in a dressed atomic system: Polarization interference in a Doppler-broadened system". United States. doi:10.1103/PHYSREVA.75.023805.
@article{osti_20982181,
title = {Two-photon resonant four-wave mixing in a dressed atomic system: Polarization interference in a Doppler-broadened system},
author = {Zuo, Zhanchun and Liu, Xia and Wu, Ling-An and Fu, Panming and Sun, Jiang},
abstractNote = {We study dressed-atom two-photon resonant nondegenerate four-wave mixing (NFWM) in a Doppler-broadened system. It is found that there exists interference between the macroscopic field polarizations from different ensembles of atoms within the atomic velocity distribution. This polarization interference can cause significant modification of the NFWM spectra. We also show that two-photon resonant NFWM in dressed atoms can be employed as a new type of Doppler-free high-resolution Autler-Townes spectroscopy for measuring transition dipole moments between two highly excited atomic states.},
doi = {10.1103/PHYSREVA.75.023805},
journal = {Physical Review. A},
number = 2,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
  • We study two-photon resonant nondegenerate four-wave mixing (NFWM) in a dressed cascade four-level system. In the presence of a strong coupling field, the two-photon resonant NFWM spectrum exhibits Autler-Townes splitting, accompanied by either suppression or enhancement of the NFWM signal. Such phenomena are demonstrated in Ba through inducing of atomic coherence between the ground state 6s{sup 2} and the doubly excited autoionizing Rydberg state 6pnd. This technique provides a spectroscopic tool for measuring not only the resonant frequency and dephasing rate but also the transition dipole moment between two highly excited atomic states.
  • Polarization properties of pure four-wave mixing (FWM) and dressed-FWM processes in a two-level system and a cascade three-level atomic system are theoretically and experimentally investigated. The relative intensities and polarization characteristics of the FWM signals in different laser polarization configurations and different level systems are experimentally investigated and compared. Also, the results are theoretically explained by different transition paths combinations. In the dressed-FWM processes, we study the dependence of dressing effect on the incident field's polarization. The FWM signal generated by a linearly polarized pumping field is suppressed more by the dressing field than the one generated by a circularlymore » polarized pumping field. However, an opposite effect was observed when the probe field's polarization is changed. The multidressing mechanisms are used to explain these effects. In addition, the interference and polarization dependence of the coexisting FWM signals in the same atomic system are discussed.« less
  • Through multiphoton ionization measurements, the polarization effects in destructive quantum interference under three-photon resonant excitation have been studied. Recent observations [V. Peet, Phys. Rev. A 74, 033406 (2006)] have indicated that contrary to the well-known pattern of a total suppression of resonance excitation, the destructive interference becomes incomplete if three-photon transition is driven by crossed beams with orthogonal polarization planes. These observations have been tested for a more general case of two-color excitation and very similar polarization-dependent anomalies in the interference character have been registered. It has been shown that the destructive interference is modified and the resonance excitation doesmore » occur if two crossed laser beams have opposite circular polarizations. The pressure-induced evolution of the uncanceled ionization peaks has the ratio of blue shift to width close to 0.5 exactly as it is known for resonance ionization peaks registered under excitation by counterpropagating laser beams.« less
  • Three-photon excitation and associated wave mixing near the 6s and 6s{sup '} resonances of xenon have been studied utilizing resonance-enhanced multiphoton ionization in angled beams with different polarizations. It has been shown that a complete cancellation of three-photon resonant atomic excitation caused by the well-known destructive wave-mixing interference occurs in s and p polarization of angled beams but distinct resonance ionization enhancement is observed when pump beams have orthogonal polarization planes. Pressure-induced evolution of the resonance ionization peak in cross-polarized beams is identical to that observed with counterpropagating beams. The reason for such resonance ionization enhancement is unknown and cannotmore » be explained within the frame work of existing theory. The effect may result from some peculiarities of wave-mixing interference in a multilevel atomic system, where different degenerate magnetic sublevels of the upper atomic state and multiple interfering excitation processes are involved. Another possibility is that the resonance ionization enhancement results from a process where weak counterpropagating light is generated within the excitation region of cross-polarized angled beams.« less
  • Competitive inhibition of a resonance enhanced multiphoton ionization process by a resonant four-wave mixing has been observed in Xe atoms. When an intense IR (1064 nm) laser was applied to a sample of Xe which was also being irradiated by a UV laser tuned to the two-photon absorption line of Xe, the two-photon-resonant three-photon ionization signals decreased with increasing IR laser power. This phenomenon is dependent on the resonant states of Xe and the polarization of the two laser beams. Three 6s excited states [5/2]{sub 2}, [3/2]{sub 2}, and [1/2]{sub 0} were examined. At the [1/2]{sub 0} resonant state, themore » ion signals were not decreased but slightly increased with the increase of the IR laser power. No suppression of the ion signal was observed at the [5/2]{sub 2} resonant state, when the polarization directions of the lasers were perpendicular to each other. The result of the polarization dependence reflects the selection rules of four-wave mixing. A simple rate equation analysis including the contribution of two-photon ionization from the [1/2]{sub 0} state by the IR laser well represents the IR laser-power dependence of the ion signal.« less