© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Physical Review A

Conical fluorescence emission from sodium vapor excited with tunable femtosecond light pulses

Virgilijus Vaičaitis, E. Gaižauskas

Published Mar 16, 2007• 14 citations

Abstract

An experimental and theoretical investigation is made of the angular spectrum of a near-resonant femtosecond laser pulse propagating through sodium vapor. A directional fluorescence emission corresponding to single-photon sodium transition $3S\ensuremath{\rightarrow}3{P}_{1∕2,3∕2}$ has been registered for the pump wavelength ranging from $540\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}605\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. It is found that such emission can be detected under the conditions of single-photon (enhanced by two-photon) resonance of pump frequency with relevant atomic states. Theoretical treatment of the field-matter interaction by means of the nonperturbative (semiclassical) approach revealed conical components of the cylindrically symmetric beam spectrum originating both from the fluorescence induced by coherent atomic polarization and four-wave mixing.

DOI: 10.1103/physreva.75.033808

Related papers

Conical Emission from Sodium Vapor Excited with Femtosecond Light Pulses

Virgilijus Vaičaitis

Two distinct types of the cones, red-shifted in respect to the single-photon sodium transition 3S-3P have been registered simultaneously for the pump wavelength tuned between 540 and 585 nm. Parametric four-photon superfluorescence was also detected

Quantum Electronics and Laser Science Conference•Dec 10, 2005•0 citations

Spectral and spatial evolution of a conical emission in Na vapor

Alexander A. Dreischuh, Vladimir P. Kamenov, Stoyan Dinev +3 more

A detailed study on yellow conical emission observed in dense sodium vapor following near-resonant one-photon excitation of the Na 42P levels was performed. The origins of conical emission are suggested to be due to Raman resonant four-wave parametric mixing processes. In order to describe spectral and spatial features of off-axis emission, we introduce self-phase modulation and induced-phase modulation as important additional nonlinear processes, explaining the nonmonotonic detuning of the wavelength of the conical radiation with the exiting laser wavelength in the vicinity of resonance transitions. The spatial evolution of emission generated via four-wave mixing is modeled by solving the two-dimensional nonlinear Schrödinger equation describing the spatial evolution of light beams in a nonlinear media. Experimental and theoretical results are presented and discussed.

Journal of the Optical Society of America B•Jan 1, 1998•9 citations

Nonlinear optical processes in sodium vapour excited with tunable femtosecond light pulses

Virgilijus Vaičaitis, E. Gaižauskas, T. Lipinskas

This paper presents the results of the investigations of nonlinear optical processes in sodium vapour excited with tunable femtosecond light pulses. Efficient four-photon parametric superfluorescence along with the two different types of conical emission from sodium vapor have been demonstrated and analyzed for a wide (over 1200 cm/sup -1/) tuning range of femtosecond pump pulses.

European Quantum Electronics Conference (EQEC)•Jan 18, 2006•0 citations

Multiple conical emissions from a strongly driven atomic system

Yaakov Shevy, M. Rosenbluh

Two distinct forms of conical emission are observed when a strong near-resonant laser pulse propagates through sodium vapor. One of the cones originates in a resonantly enhanced parametric four-wave mixing process. A spatially and spectrally distinct cone is produced by the radiative decay of the coherently prepared population of the excited state at a frequency close to that of the unperturbed atomic resonance.

Journal of the Optical Society of America B•Jan 1, 1988•34 citations

Conical emission due to four-wave mixing enhanced by the ac Stark effect in self-trapped filaments of light

Donald J. Harter, Robert W. Boyd

Experimental evidence is presented that shows that the conical emission often found surrounding a near-resonant laser beam after it passes through an atomic vapor is due to nondegenerate four-wave mixing enhanced by the ac Stark effect. We demonstrate self-trapping of a pulsed dye-laser beam in sodium vapor for wavelengths 0.04 to 10 A shorter than that of the D(2) resonance and show that the four-wave mixing process leading to conical emission occurs within these self-trapped filaments.

Optics Letters•Oct 1, 1982•15 citations

Conical Stokes emission in three-level systems as a coherent propagation effect

Steven F. DiMarco, Cyrus D. Cantrell, Michael E. Crenshaw

It is now known that conical emission in a two-level atomic system is a fundamental propagation effect brought about by the breakup of the exciting laser pulse into solitary waves.1 This report presents a semiclassical numerical calculation that extends this previous work by solving the optical Bloch and Maxwell equations for a three-level atomic vapor excited by laser fields of two different frequencies. The applied fields satisfy a two-photon resonance condition between the ground and final states and are slightly detuned from the intermediate state to enhance the nonlinear polarization.2 As the fields propagate, oscillations in the nonlinear polarization of the pump beam dominate the interaction and lead to the pump's breakup into solitary waves. The Stokes polarization, depending on the pump radiation, also experiences these oscillations. Because of the intensity-dependence of the refractive index, the solitary waves experience a curvature in the time-radius plane. This curvature manifests itself in the spectrum as a radial component of the wave vector at the Rabi frequency. The Stokes field, experiencing parametric breakup, displays a similar curvature. Spectral analysis reveals a radial component of the Stokes wave vector as well. This frequency-shifted off-axis radiation is identified as conical emission in the Stokes field.

Annual Meeting Optical Society of America•Jan 1, 1990•0 citations

An experimental and theoretical investigation is made of the angular spectrum of a near-resonant femtosecond laser pulse propagating through sodium vapor. A directional fluorescence emission corresponding to single-photon sodium transition

3S\ensuremath{\rightarrow}3{P}_{1∕2,3∕2}

has been registered for the pump wavelength ranging from

540\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}605\phantom{\rule{0.3em}{0ex}}\mathrm{nm}

. It is found that such emission can be detected under the conditions of single-photon (enhanced by two-photon) resonance of pump frequency with relevant atomic states. Theoretical treatment of the field-matter interaction by means of the nonperturbative (semiclassical) approach revealed conical components of the cylindrically symmetric beam spectrum originating both from the fluorescence induced by coherent atomic polarization and four-wave mixing.

A detailed study on yellow conical emission observed in dense sodium vapor following near-resonant one-photon excitation of the Na 42P levels was performed. The origins of conical emission are suggested to be due to Raman resonant four-wave parametric mixing processes. In order to describe spectral and spatial features of off-axis emission, we introduce self-phase modulation and induced-phase modulation as important additional nonlinear processes, explaining the nonmonotonic detuning of the wavelength of the conical radiation with the exiting laser wavelength in the vicinity of resonance transitions. The spatial evolution of emission generated via four-wave mixing is modeled by solving the two-dimensional nonlinear Schrödinger equation describing the spatial evolution of light beams in a nonlinear media. Experimental and theoretical results are presented and discussed.

It is now known that conical emission in a two-level atomic system is a fundamental propagation effect brought about by the breakup of the exciting laser pulse into solitary waves.1 This report presents a semiclassical numerical calculation that extends this previous work by solving the optical Bloch and Maxwell equations for a three-level atomic vapor excited by laser fields of two different frequencies. The applied fields satisfy a two-photon resonance condition between the ground and final states and are slightly detuned from the intermediate state to enhance the nonlinear polarization.2 As the fields propagate, oscillations in the nonlinear polarization of the pump beam dominate the interaction and lead to the pump's breakup into solitary waves. The Stokes polarization, depending on the pump radiation, also experiences these oscillations. Because of the intensity-dependence of the refractive index, the solitary waves experience a curvature in the time-radius plane. This curvature manifests itself in the spectrum as a radial component of the wave vector at the Rabi frequency. The Stokes field, experiencing parametric breakup, displays a similar curvature. Spectral analysis reveals a radial component of the Stokes wave vector as well. This frequency-shifted off-axis radiation is identified as conical emission in the Stokes field.