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

Journal of Applied Physics

Cascade emission and four-wave mixing parametric processes in potassium

Thomas Efthimiopoulos, M. E. Movsesyan, M. Katharakis, Nikolaos Merlemis

Published Jul 15, 1996• 21 citations
Publisher

Abstract

Strong stimulated cascade emission and coherent four-wave parametric radiations are observed. By proper observation of the excitation spectra, the cascade emission and the coherent four-wave mixing parametric processes can be identified. The effect of the buffer gas pressure on the intensity and the pulse compression of the emitted radiation were investigated. Cascade inversionless coherent radiation emission with absorption reduction and third order nonlinear susceptibility enhancement due to the presence of a strong internally generated field are discussed for the 4p–4s strong emission observed.

DOI
10.1063/1.362872

Related papers

Four-wave mixing and parametric four-wave mixing near the 4P 4S transition of the potassium atom

M. Katharakis, Nikolaos Merlemis, Alexander A. Serafetinides +1 more

Potassium 4S 1/2 –6S 1/2 two-photon excitation initiates the emission of several internally generated photons. For the first time two emission lines, one close to and one below the potassium 4P 3/2 level, are reported for low pumping intensity. Radiation emitted below the 4P 3/2 level is due to a parametric four-wave mixing process that uses the photons emitted at the 5P 3/2 –4S 1/2 transition and a two-step four-wave mixing process generates the line emitted close to the 4P 3/2 level.

Journal of Physics B Atomic Molecular and Optical Physics•Nov 27, 2002•23 citations

Study of the emission in K under two-photon excitation

Thomas Efthimiopoulos, M. E. Movsesyan, M. Katharakis +2 more

It is shown that by proper use of the excitation spectra, the emission spectra of the transition and the far-field patterns it is possible to distinguish between competing processes involved in the two-photon excitation to the 6S state of potassium, namely: (a) resonant fluorescence emission associated with the cascading spontaneous emission (ASE) and (b) the four-wave mixing parametric process. The effect of the buffer gas on the intensities of the spectra of the radiations emitted is discussed. Conical emission and spatial instabilities of the excitation radiation and the emission were also observed for high excitation and high vapour pressure of potassium.

Journal of Physics B Atomic Molecular and Optical Physics•Nov 28, 1996•9 citations

Stimulated emissions and quantum interference in potassium atom laser interaction

Nikolaos Merlemis, M. Katharakis, E. Koudoumas +1 more

The interaction of a laser with potassium atoms is investigated by monitoring the radiation of the 5P-4S transition under the two-photon 4S(1/2)-6S(1/2) excitation. For low number density and laser intensity the observed radiation is parametric axial or conical, depending on the laser detuning from the two-photon resonance, the number density and the laser intensity. With increasing laser intensities and number densities, an additional delayed component is observed corresponding to a two-step four-wave mixing with the participation of internally generated photons. A two-photon quantum interference effect is observed for the total (axial and conical) parametric four-wave mixing emission. A deviation from the proposed model under certain experimental parameters is attributed to a two-step four-wave mixing and the phase mismatch of the parametric processes.

Journal of Physics B Atomic Molecular and Optical Physics•May 2, 2003•15 citations

Four-wave mixing near the 4P-4S transition of a potassium atom

M. Katharakis, Nikolaos Merlemis, Alexandros A. Serafetinides +1 more

Potassium 4S1/2 - 6S1/2 two-photon excitation initiates the emission of several internally generated photons. For the first time two emission lines one close and one below the potassium 4P3/2 level are reported. Radiation emitted below the 4P3/2 - 4S1/2 level is due to a Parametric Four Wave Mixing (PFWM) process initiated by the internally generated radiation from 5P3/2 - 4S1/2 level. The line emitted close to the 4P3/2 level is produced by a two-step Four Wave Mixing (FWM) process. Direct one photon driving of 4S3/2 - 4P3/2 transition produces similar to HEP radiation.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 11, 2003•0 citations

Emissions in potassium vapour under 4S[sub 1∕2]–7S[sub 1∕2] two-photon nsec excitation

Dionysios Pentaris, George Chatzikyriakos, A. Armyras +6 more

The two‐photon excitation of 4S1/2–7S1/2 transition of potassium atoms is studied. Several coherent emissions and processes are possible, such as parametric four‐wave (PFWM), parametric six‐wave (PSWM) mixing and competition with the stimulated hyper Raman (SHRS) and the amplified spontaneous emission (ASE). The radiations at the transitions 6P3/2,1/2−4S1/2, 6S1/2−4P3/2,1/2 and 5P3/2,1/2−4S1/2 are emitted only in the forward direction (indicating a parametric process), while the radiation at the transition 4P3/2,1/2−4S1/2 is emitted in the forward and in the backward direction, indicating an ASE process.

AIP conference proceedings•Jan 1, 2010•2 citations

Wave-mixing processes in sodium-potassium vapor

Brian K. Clark, Mark F. Masters, John Huennekens

We report observations of 4‐wave and 6‐wave mixing processes based upon two‐photon pumping of the potassium 4S→6S and 4S→4D transitions in a sodium‐potassium mixture. Additionally we observe coherent emissions at the potassium 3D→4P transition frequencies for pump wavelengths between 725 and 760 nm. The excitation spectra for these emissions show several broad peaks, each of roughly 10 nm width. A series of sharp dips is superimposed on the most intense peak due to depletion of the 3D population by laser‐induced absorption to Rydberg F levels. Although the 3D→4P emissions can be observed in both the forward and backward directions, they are ∼50 times more intense in the forward direction. We believe the forward emission is primarily due to 6‐wave mixing while the backward emission can most likely be attributed to amplified spontaneous emission following two‐photon molecular photodissociation. However, at present, the exact mechanisms responsible for these 3D→4P emissions are not fully understood.

AIP conference proceedings•Jan 1, 1988•1 citation
Strong stimulated cascade emission and coherent four-wave parametric radiations are observed. By proper observation of the excitation spectra, the cascade emission and the coherent four-wave mixing parametric processes can be identified. The effect of the buffer gas pressure on the intensity and the pulse compression of the emitted radiation were investigated. Cascade inversionless coherent radiation emission with absorption reduction and third order nonlinear susceptibility enhancement due to the presence of a strong internally generated field are discussed for the 4p–4s strong emission observed.
It is shown that by proper use of the excitation spectra, the emission spectra of the transition and the far-field patterns it is possible to distinguish between competing processes involved in the two-photon excitation to the 6S state of potassium, namely: (a) resonant fluorescence emission associated with the cascading spontaneous emission (ASE) and (b) the four-wave mixing parametric process. The effect of the buffer gas on the intensities of the spectra of the radiations emitted is discussed. Conical emission and spatial instabilities of the excitation radiation and the emission were also observed for high excitation and high vapour pressure of potassium.
The interaction of a laser with potassium atoms is investigated by monitoring the radiation of the 5P-4S transition under the two-photon 4S(1/2)-6S(1/2) excitation. For low number density and laser intensity the observed radiation is parametric axial or conical, depending on the laser detuning from the two-photon resonance, the number density and the laser intensity. With increasing laser intensities and number densities, an additional delayed component is observed corresponding to a two-step four-wave mixing with the participation of internally generated photons. A two-photon quantum interference effect is observed for the total (axial and conical) parametric four-wave mixing emission. A deviation from the proposed model under certain experimental parameters is attributed to a two-step four-wave mixing and the phase mismatch of the parametric processes.
Potassium 4S1/2 - 6S1/2 two-photon excitation initiates the emission of several internally generated photons. For the first time two emission lines one close and one below the potassium 4P3/2 level are reported. Radiation emitted below the 4P3/2 - 4S1/2 level is due to a Parametric Four Wave Mixing (PFWM) process initiated by the internally generated radiation from 5P3/2 - 4S1/2 level. The line emitted close to the 4P3/2 level is produced by a two-step Four Wave Mixing (FWM) process. Direct one photon driving of 4S3/2 - 4P3/2 transition produces similar to HEP radiation.
The two‐photon excitation of 4S1/2–7S1/2 transition of potassium atoms is studied. Several coherent emissions and processes are possible, such as parametric four‐wave (PFWM), parametric six‐wave (PSWM) mixing and competition with the stimulated hyper Raman (SHRS) and the amplified spontaneous emission (ASE). The radiations at the transitions 6P3/2,1/2−4S1/2, 6S1/2−4P3/2,1/2 and 5P3/2,1/2−4S1/2 are emitted only in the forward direction (indicating a parametric process), while the radiation at the transition 4P3/2,1/2−4S1/2 is emitted in the forward and in the backward direction, indicating an ASE process.
We report observations of 4‐wave and 6‐wave mixing processes based upon two‐photon pumping of the potassium 4S→6S and 4S→4D transitions in a sodium‐potassium mixture. Additionally we observe coherent emissions at the potassium 3D→4P transition frequencies for pump wavelengths between 725 and 760 nm. The excitation spectra for these emissions show several broad peaks, each of roughly 10 nm width. A series of sharp dips is superimposed on the most intense peak due to depletion of the 3D population by laser‐induced absorption to Rydberg F levels. Although the 3D→4P emissions can be observed in both the forward and backward directions, they are ∼50 times more intense in the forward direction. We believe the forward emission is primarily due to 6‐wave mixing while the backward emission can most likely be attributed to amplified spontaneous emission following two‐photon molecular photodissociation. However, at present, the exact mechanisms responsible for these 3D→4P emissions are not fully understood.