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

NASA STI/Recon Technical Report N

Theoretical Studies of Squeezed-State Generation in Propagating Laser Beams

Cyrus D. Cantrell

Published Sep 28, 1990• 0 citations
OpenAlex

Abstract

Abstract : This research investigated the feasibility of generating squeezed states of light using the conical emission that occurs when a nearly resonant laser beam propagates in an atomic vapor. Preliminary results indicate that a high degree of squeezing may be obtained in pulses. Methods were developed for the inclusion of diffraction and transverse effects. Keywords: Laser-pulse propagation.

Related papers

Temporal and spatial modulation in laser-pulse propagation

Michael E. Crenshaw, C. D. Cantrell

An intense laser pulse that is nearly resonant with an atomic transition and that can initially be described as smooth and nearly adiabatic can acquire significant temporal and spatial modulation as the result of propagation through an atomic vapor. Computer calculations demonstrate that the temporal modulation is a result of enhancement, under propagation, of the initially small nonadiabatic portion of the transient nonlinear atomic response. The transient nonlinear atomic response varies with the field strength so that the transverse variation in field strength results in a spatial modulation, known as conical emission.

Optics Letters•May 1, 1988•12 citations

Temporal and spatial modulation in laser propagation

Michael E. Crenshaw, Cyrus D. Cantrell

Observations of a frequency-shifted coherent conical emission from systems pumped by an intense optical field that is nearly resonant with a one-photon transition1 have made it clear that propagation effects can play a major role in determining the spectrum as well as the spatial characteristics of the transmitted pulse. Proposed theories of conical emission stress the importance of transverse effects leading to four-wave mixing1 or spatial self-phase modulation.2 We report computer results on laser propagation in a two-level system and demonstrate that spatial structure, including conical emission, can result from temporal propagation effects.

Conference on Lasers and Electro-Optics•Apr 25, 1988•0 citations

Conical emission and coherent sideband generation in laser propagation

Michael E. Crenshaw, Cyrus D. Cantrell

Computational results show that the conical emission and Rabi sidebands observed when a nearly resonant laser pulse propagates through an atomic vapor are the result of the breakup of the pulse into solitary waves. For an incident pulse with a transverse as well as a temporal profile, the crests and troughs of the 2-D solitary waves are curved in a time-radius plane. The temporal modulation associated with pulse breakup appears as Rabi sidebands in the spectrum, while the curvature of the solitary waves in the time-radius plane results in a transverse spatial modulation, resulting in conical emission in the far field. These results were obtained by performing detailed numerical calculations of the time-dependent paraxial propagation of a cylindrically symmetric laser pulse through a vapor of two-level atoms. Our results can be interpreted readily in terms of optical nutation on the Bloch sphere and in terms of noncollinear phase matching through the curvature of the solitary waves rather than through additional parametrically generated waves. The cone opening angle depends on the initial transverse profile of the pulse and the process of beam breakup as well as self-focusing.

Annual Meeting Optical Society of America•Jan 1, 1988•0 citations

Theory of optical near-resonant cone emission in atomic vapor

B. D. Paul, J. Cooper, Alan Gallagher +1 more

A time-dependent theory for conical emission during near-resonant propagation of laser light in an atomic vapor, which includes full propagation for the laser and frequency sidebands in a nonlinear two-level medium is presented. The density-matrix equations for the dipole moment and population are solved in the dressed atomic frame. The polarization source terms are accurate to order \ensuremath{\gamma}/R, where \ensuremath{\gamma} is a damping constant and R is the generalized Rabi frequency. Analytical plane-wave solutions and numerical, cylindrically symmetric propagation simulations including diffraction are presented. It is shown that the calculations with cylindrically symmetric fields and atomic excitation profiles are incapable of accounting for the high levels of optical gain that are responsible for the intense conical emission observed in experiments. This result is at first surprising, since the model accounts rigorously for all of the physical phenomena that have been previously proposed as being responsible for generating large gains, and the calculation matches the symmetry of the observations. The lack of large calculated gain seems to imply the existence of higher-order $(m>0)$ radial modes in the field for the experimental conditions that give rise to cone emission. In the simulations, however, the cylindrically symmetric fields do produce weak red-detuned cones with angular-frequency distributions similar to those seen in experiments.

Physical Review A•Dec 31, 2002•8 citations

Squeezed states in the case of parametric amplification in diffracted light beams

Sergei A. Akhmanov, А. В. Белинский, Anatolii S Chirkin

A theory of generation of squeezed states of an optical field is developed for parametric interactions of diffracted beams. It is shown that diffraction results in degradation of the squeezing process. Systems for the formation of beams that can compensate for this effect are considered.

Soviet Journal of Quantum Electronics•May 31, 1988•8 citations

On the origin of the so called conical emission in laser pulse propagation in atomic vapor

Eve A. Chauchard, Y.H. Meyer

Optics Communications•Nov 1, 1984•33 citations
Abstract : This research investigated the feasibility of generating squeezed states of light using the conical emission that occurs when a nearly resonant laser beam propagates in an atomic vapor. Preliminary results indicate that a high degree of squeezing may be obtained in pulses. Methods were developed for the inclusion of diffraction and transverse effects. Keywords: Laser-pulse propagation.
An intense laser pulse that is nearly resonant with an atomic transition and that can initially be described as smooth and nearly adiabatic can acquire significant temporal and spatial modulation as the result of propagation through an atomic vapor. Computer calculations demonstrate that the temporal modulation is a result of enhancement, under propagation, of the initially small nonadiabatic portion of the transient nonlinear atomic response. The transient nonlinear atomic response varies with the field strength so that the transverse variation in field strength results in a spatial modulation, known as conical emission.
Observations of a frequency-shifted coherent conical emission from systems pumped by an intense optical field that is nearly resonant with a one-photon transition1 have made it clear that propagation effects can play a major role in determining the spectrum as well as the spatial characteristics of the transmitted pulse. Proposed theories of conical emission stress the importance of transverse effects leading to four-wave mixing1 or spatial self-phase modulation.2 We report computer results on laser propagation in a two-level system and demonstrate that spatial structure, including conical emission, can result from temporal propagation effects.
Computational results show that the conical emission and Rabi sidebands observed when a nearly resonant laser pulse propagates through an atomic vapor are the result of the breakup of the pulse into solitary waves. For an incident pulse with a transverse as well as a temporal profile, the crests and troughs of the 2-D solitary waves are curved in a time-radius plane. The temporal modulation associated with pulse breakup appears as Rabi sidebands in the spectrum, while the curvature of the solitary waves in the time-radius plane results in a transverse spatial modulation, resulting in conical emission in the far field. These results were obtained by performing detailed numerical calculations of the time-dependent paraxial propagation of a cylindrically symmetric laser pulse through a vapor of two-level atoms. Our results can be interpreted readily in terms of optical nutation on the Bloch sphere and in terms of noncollinear phase matching through the curvature of the solitary waves rather than through additional parametrically generated waves. The cone opening angle depends on the initial transverse profile of the pulse and the process of beam breakup as well as self-focusing.
A time-dependent theory for conical emission during near-resonant propagation of laser light in an atomic vapor, which includes full propagation for the laser and frequency sidebands in a nonlinear two-level medium is presented. The density-matrix equations for the dipole moment and population are solved in the dressed atomic frame. The polarization source terms are accurate to order \ensuremath{\gamma}/R, where \ensuremath{\gamma} is a damping constant and R is the generalized Rabi frequency. Analytical plane-wave solutions and numerical, cylindrically symmetric propagation simulations including diffraction are presented. It is shown that the calculations with cylindrically symmetric fields and atomic excitation profiles are incapable of accounting for the high levels of optical gain that are responsible for the intense conical emission observed in experiments. This result is at first surprising, since the model accounts rigorously for all of the physical phenomena that have been previously proposed as being responsible for generating large gains, and the calculation matches the symmetry of the observations. The lack of large calculated gain seems to imply the existence of higher-order (m>0)(m>0)(m>0) radial modes in the field for the experimental conditions that give rise to cone emission. In the simulations, however, the cylindrically symmetric fields do produce weak red-detuned cones with angular-frequency distributions similar to those seen in experiments.