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

Improving the angular response of DFWM in atomic vapors

David S. Glassner, B. Ai, R. J. Knize, J. P. Partenan, R. W. Hellwarth

Published May 8, 1994• 0 citations
OpenAlex

Abstract

Atomic vapors, such as those of Na, K, and Cs, have such a large and fast nonlinear response on or near resonances that they are capable of processing images, with milliwatt lasers at submicrosecond time scales. However, the atomic motion can wash out the induced population gratings, so that the degenerate four-wave-mixing (DFWM) signal is greatly reduced for angles above -10 mrad.

Related papers

Improved angular response of degenerate four-wave mixing in K vapor

David S. Glassner, B. Ai, R. J. Knize +2 more

Atomic vapors, such as Na, K, and Cs, have such a large and fast nonlinear response on or near resonances that they are capable of processing high resolution images with cw lasers at submicrosecond time scales.

Annual Meeting Optical Society of America•Jan 1, 1993•0 citations

Degenerate Four Wave Mixing In Cesium Vapor

Randall J. St. Pierre, Alexander B. Horwitz, J C. Brock

The work reported here demonstrates for the first time degenerate four wave mixing (DFWM) phase conjugation in cesium (Cs) atomic vapor. The strong, spectrally narrow transition of cesium at 852 nm gives conjugate reflectivities up to 154% with low pump beam powers. Temperature tuning of the DFWM response over a 30 GHz bandwidth is also demonstrated. An improved experimental design to determine the DFWM angular response shows a field-of-view of 20 mrad at the half response points. Self-focusing effects are observed to be similar to those in sodium vapor with an onset of increased conjugate divergence for reflectivities greater than about 25%.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 8, 1988•3 citations

Radiation trapping and light shift in DFM in Na vapor

Wulfhard K. Lange, M. Schiffer, E. Cruse +1 more

The influence of radiation trapping on degenerate four-wave-mixing (DFWM) processes has recently been discussed theoretically.1 Its role in the nonlinear behavior of sodium atoms in a buffer-gas atmosphere has also been examined.2 We used an experimental scheme similar to that reported in Ref. 3 to study its influence on DFWM in dense sodium vapor (1013 -1014 atoms cm −3).

•May 8, 1994•0 citations

Degenerate four-wave mixing in resonant saturable material

Duncan G. Steel, Richard C. Lind, Juan Francisco Lam +1 more

The nonlinear response of resonant saturable materials giving rise to degenerate four-wave mixing (DFWM) has been shown both experimentally and theoretically to provide the potential for very large efficiencies for phase conjugation and Doppler-free spectra for high resolution spectroscopy. The geometry for this interaction consists of two counter- propagating pumps (Ef and Ep) and a probe (Ep) intersecting the pumps at some angle θfp. The simultaneous action of one pump and the probe produces spatial hole burning resulting in a spatial modulation of the saturating absorption and dispersion which scatters the remaining pump to produce the signal.

Conference on Lasers and Electro-Optics•Jan 1, 1981•0 citations

Enhancement of degenerate four-wave mixing by atom-wall collisions in atomic vapors

B. Ai, David S. Glassner, R. J. Knize

Resonant cw degenerate four-wave mixing signals usually are not observed at noncycling transitions in alkali-metal vapors due to population depletion from optical pumping. We demonstrate that frequent atom-wall collisions can overcome the effects of optical pumping when atomic vapors are contained in thin cells. Significantly enhanced degenerate four-wave mixing signals are observed at noncycling transitions, and they are comparable in magnitude to the signals observed at cycling transitions in thin cells. This technique extends the utilization of degenerate four-wave mixing to noncycling transitions in atoms or molecules.

Physical Review A•Oct 1, 1994•21 citations

Degenerate four-wave mixing from laser-populated excited states

Peter Ljungberg, Ove Axner

Degenerate four-wave mixing (DFWM) from laser-populated excited states, i.e., two-step DFWM (2S-DFWM), has been performed to investigate the possibility of increasing signal quality (i.e., strength or signal-to-noise ratio) when species with low transition probabilities or far-UV transitions are to be detected or when large beam areas are used. Gold atoms, aspirated into an air-acetylene flame, were chosen as a suitable species for this investigation. The 2S-DFWM signal strength was found to be comparable to the ordinary (one-step) DFWM signals for moderately high UV-light intensities but substantially better for low UV-light intensities. This finding implies that DFWM detection of species with lower transition probabilities in the first step as compared with gold (<10(-8) s(-1)) can benefit from the 2S-DFWM technique when moderate or low UV-light intensities are available. Additional possible advantages of using 2S-DFWM are also discussed.

Applied Optics•Jan 20, 1995•9 citations
Atomic vapors, such as those of Na, K, and Cs, have such a large and fast nonlinear response on or near resonances that they are capable of processing images, with milliwatt lasers at submicrosecond time scales. However, the atomic motion can wash out the induced population gratings, so that the degenerate four-wave-mixing (DFWM) signal is greatly reduced for angles above -10 mrad.
The work reported here demonstrates for the first time degenerate four wave mixing (DFWM) phase conjugation in cesium (Cs) atomic vapor. The strong, spectrally narrow transition of cesium at 852 nm gives conjugate reflectivities up to 154% with low pump beam powers. Temperature tuning of the DFWM response over a 30 GHz bandwidth is also demonstrated. An improved experimental design to determine the DFWM angular response shows a field-of-view of 20 mrad at the half response points. Self-focusing effects are observed to be similar to those in sodium vapor with an onset of increased conjugate divergence for reflectivities greater than about 25%.
The nonlinear response of resonant saturable materials giving rise to degenerate four-wave mixing (DFWM) has been shown both experimentally and theoretically to provide the potential for very large efficiencies for phase conjugation and Doppler-free spectra for high resolution spectroscopy. The geometry for this interaction consists of two counter- propagating pumps (Ef and Ep) and a probe (Ep) intersecting the pumps at some angle θfp. The simultaneous action of one pump and the probe produces spatial hole burning resulting in a spatial modulation of the saturating absorption and dispersion which scatters the remaining pump to produce the signal.
Resonant cw degenerate four-wave mixing signals usually are not observed at noncycling transitions in alkali-metal vapors due to population depletion from optical pumping. We demonstrate that frequent atom-wall collisions can overcome the effects of optical pumping when atomic vapors are contained in thin cells. Significantly enhanced degenerate four-wave mixing signals are observed at noncycling transitions, and they are comparable in magnitude to the signals observed at cycling transitions in thin cells. This technique extends the utilization of degenerate four-wave mixing to noncycling transitions in atoms or molecules.
Degenerate four-wave mixing (DFWM) from laser-populated excited states, i.e., two-step DFWM (2S-DFWM), has been performed to investigate the possibility of increasing signal quality (i.e., strength or signal-to-noise ratio) when species with low transition probabilities or far-UV transitions are to be detected or when large beam areas are used. Gold atoms, aspirated into an air-acetylene flame, were chosen as a suitable species for this investigation. The 2S-DFWM signal strength was found to be comparable to the ordinary (one-step) DFWM signals for moderately high UV-light intensities but substantially better for low UV-light intensities. This finding implies that DFWM detection of species with lower transition probabilities in the first step as compared with gold (<10(-8) s(-1)) can benefit from the 2S-DFWM technique when moderate or low UV-light intensities are available. Additional possible advantages of using 2S-DFWM are also discussed.