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

Laser Chemistry

Two‐Photon Resonant Third Harmonic Generation IN Hg

E. Koudoumas, Thomas Efthimiopoulos

Published Jan 1, 1993• 4 citations
Publisher

Abstract

Third‐harmonic generation in Hg vapors, using the two‐photon resonance 61S0–81S0 transition is theoretically and experimentally investigated. Calculations of the Hg contribution to the phase mismatch are presented and the effects of the absorption of the radiation, the population transfer, the saturation, and the ionization on the efficiency of the system are considered. It is shown that the population transfer is the dominant mechanism affecting the efficiency.

DOI
10.1155/1993/29594

Related papers

Coherent Resonant Interaction and Harmonic Generation in Atomic Vapors.

Nandini Mukherjee

This work examines the use of higher order multiphoton resonances in higher harmonic generation together with judicious exploitation of coherent interaction properties to achieve efficient harmonic generation. A detailed experimental study on third harmonic generation in two photon resonant coherent interaction and a theoretical study on four photon resonant coherent interaction have been conducted. Two photon resonant coheren propagation in lithium vapor (2S-4S and 2S-3D interaction) has been studied in detail as a function of phase and delay of the interacting pulse sequence. Under coherent lossless propagation of 90 phase shifted pulse pair, third harmonic generation is enhanced. A maximum energy conversion efficiency of 1% was measured experimentally. This experiment shows that phase correlated pulse sequence can be used to control multiphoton coherent resonant effects. A larger two photon resonant enhancement does not result in more efficient harmonic generation, in agreement with the theoretical prediction. An accurate (to at least 0.5 A°) measurement of intensity dependent Stark shift has been done with the newly developed "interferometric wavemeter." Stark shifts as big as several pulse bandwidths (of picosecond pulses) result in a poor tuning of multiphoton resonance and become a limiting factor of resonant harmonic generation. A complete theory has been developed for harmonic generation in a four photon resonant coherent interaction. A numerical application of the theory to the Hg atom successfully interprets the experimental observations in terms of the phase dependent stimulated Raman scattering. With the intensity required for four photon resonant transition, the calculation predicts a dramatic Stark shift effect which completely destroys the resonance condition. This model provides a basis for the development of future schemes for efficient higher order coherent upconversion.

•Aug 1, 1987•0 citations

Theory of third-harmonic generation in metal vapors under two-photon resonance conditions

A. T. Georges, P. Lambropoulos, John H. Marburger

The density-matrix formalism is used to develop the theory of two-photon-resonant third-harmonic generation in metal vapors taking into account saturation, ionization, laser-induced Stark shifts, and variations in the wave-vector mismatch as a result of population redistribution. It is shown that for third-harmonic generation in the ultraviolet and the vacuum-ultraviolet regions, where $3\ensuremath{\omega}$ exceeds the ionization limit of the metal vapor, two-photon-resonant three-photon ionization will be the main limiting process. This will also be true for four-wave parametric processes. For efficient energy conversion, the two-photon-resonant metal vapor must be phase matchable to allow large vapor density and cell length. Otherwise, the low incident intensity limits, set by the saturation and the ionization effects, cannot be efficiently converted in only one coherence length. The theory is applied to two-photon-resonant tripling of the ruby laser in cesium vapor.

Physical Review A•Jan 1, 1977•81 citations

Emission spectrum in a two-photon resonant transition in mercury

E. Koudoumas, Thomas Efthimiopoulos

The emitted spectrum in the two-photon transition resonant with the 81S0 state in Hg is experimentally investigated. A complete list of the emitted lines that are due to second-harmonic generation, frequency mixing with internally generated photons, parametric generation, Raman scattering, and dimer emission and a list of their relative intensities are presented for the first time to our knowledge.

Journal of the Optical Society of America B•Jun 1, 1993•3 citations

Coherent two-photon resonant third- and fifth-harmonic vacuum-ultraviolet generation in metal vapors

Jean‐Claude Diels, A. T. Georges

The authors present a detailed theoretical analysis of two-photon resonant third- and fifth-harmonic generation in metal vapors with picosecond laser pulses. These processes are described by self-consistent Maxwell-Bloch equations which take into account the effects of optical Stark shifts, multiphoton ionization, Doppler broadening, two-photon absorption, the reaction of the third-harmonic field on the fundamental, and a nonlinear index of refraction. As an example, a quantitative analysis of third- and fifth-harmonic generation in lithium vapor ($2s\ensuremath{-}4s$ transition) is presented. The limitations on energy conversion efficiency and the temporal as well as spectral characteristics of the harmonic pulses are investigated for two kinds of low-loss propagation fundamental pulses. It is shown that 90\ifmmode^\circ\else\textdegree\fi{} phase-shifted fundamental pulses (zero area) are more efficient than $2\ensuremath{\pi}m$ pulses. Energy conversion efficiencies of 6.5% for third-harmonic (190 nm) and 0.07% for cascade fifth-harmonic (114 nm) pulses are predicted.

Physical Review A•Apr 1, 1979•43 citations

Saturation of resonant third-harmonic generation in phase-matched systems

H. B. Puell, H. Scheingraber, C. R. Vidal

The saturation of resonant third-harmonic generation in absorbing and phase-matched high-density systems is investigated theoretically as well as experimentally. It is shown that the saturation is determined by the two-photon absorption [imaginary part of ${\ensuremath{\chi}}_{S}^{(3)}(\ensuremath{\omega})$]. It gives rise to a depletion of the fundamental wave and leads to a change of the level populations and of the effective refractive index destroying the phase matching. This has to be compared with nonresonant systems which are limited by the Kerr effect, the intensity-dependent changes of the refractive index [real part of ${\ensuremath{\chi}}_{S}^{(3)}(\ensuremath{\omega})$]. Optimum conditions for resonant systems are reported.

Physical Review A•Sep 1, 1980•47 citations

Two-Photon Resonant Third Harmonic Generation under Coherent Transient Condition

Kenji Torizuka, Norio Morita, Tatsuo Yajima

The dependence of the third harmonic intensity on the medium length under completely phase-matched and resonant conditions is discussed. It is shown that the conversion efficiency in the coherent transient case is expected to exceed that in the steady state case in a long and/or dense medium when the incident light pulse has sufficient energy. The 3S-5S transition of sodium with a 602.3 nm light is studied experimentally as a model system. The efficiency as a function of the incident light frequency and intensity is in agreement with the predictions. By eliminating the phase-mismatching effect, the dependence on the medium density is also determined. It is demonstrated that the efficiency surely increases even in the higher density of sodium.

Journal of the Physical Society of Japan•Sep 15, 1984•1 citation
Third‐harmonic generation in Hg vapors, using the two‐photon resonance 61S0–81S0 transition is theoretically and experimentally investigated. Calculations of the Hg contribution to the phase mismatch are presented and the effects of the absorption of the radiation, the population transfer, the saturation, and the ionization on the efficiency of the system are considered. It is shown that the population transfer is the dominant mechanism affecting the efficiency.
This work examines the use of higher order multiphoton resonances in higher harmonic generation together with judicious exploitation of coherent interaction properties to achieve efficient harmonic generation. A detailed experimental study on third harmonic generation in two photon resonant coherent interaction and a theoretical study on four photon resonant coherent interaction have been conducted. Two photon resonant coheren propagation in lithium vapor (2S-4S and 2S-3D interaction) has been studied in detail as a function of phase and delay of the interacting pulse sequence. Under coherent lossless propagation of 90 phase shifted pulse pair, third harmonic generation is enhanced. A maximum energy conversion efficiency of 1% was measured experimentally. This experiment shows that phase correlated pulse sequence can be used to control multiphoton coherent resonant effects. A larger two photon resonant enhancement does not result in more efficient harmonic generation, in agreement with the theoretical prediction. An accurate (to at least 0.5 A°) measurement of intensity dependent Stark shift has been done with the newly developed "interferometric wavemeter." Stark shifts as big as several pulse bandwidths (of picosecond pulses) result in a poor tuning of multiphoton resonance and become a limiting factor of resonant harmonic generation. A complete theory has been developed for harmonic generation in a four photon resonant coherent interaction. A numerical application of the theory to the Hg atom successfully interprets the experimental observations in terms of the phase dependent stimulated Raman scattering. With the intensity required for four photon resonant transition, the calculation predicts a dramatic Stark shift effect which completely destroys the resonance condition. This model provides a basis for the development of future schemes for efficient higher order coherent upconversion.
The density-matrix formalism is used to develop the theory of two-photon-resonant third-harmonic generation in metal vapors taking into account saturation, ionization, laser-induced Stark shifts, and variations in the wave-vector mismatch as a result of population redistribution. It is shown that for third-harmonic generation in the ultraviolet and the vacuum-ultraviolet regions, where $3\ensuremath{\omega}$ exceeds the ionization limit of the metal vapor, two-photon-resonant three-photon ionization will be the main limiting process. This will also be true for four-wave parametric processes. For efficient energy conversion, the two-photon-resonant metal vapor must be phase matchable to allow large vapor density and cell length. Otherwise, the low incident intensity limits, set by the saturation and the ionization effects, cannot be efficiently converted in only one coherence length. The theory is applied to two-photon-resonant tripling of the ruby laser in cesium vapor.
The authors present a detailed theoretical analysis of two-photon resonant third- and fifth-harmonic generation in metal vapors with picosecond laser pulses. These processes are described by self-consistent Maxwell-Bloch equations which take into account the effects of optical Stark shifts, multiphoton ionization, Doppler broadening, two-photon absorption, the reaction of the third-harmonic field on the fundamental, and a nonlinear index of refraction. As an example, a quantitative analysis of third- and fifth-harmonic generation in lithium vapor ($2s\ensuremath{-}4s$ transition) is presented. The limitations on energy conversion efficiency and the temporal as well as spectral characteristics of the harmonic pulses are investigated for two kinds of low-loss propagation fundamental pulses. It is shown that 90\ifmmode^\circ\else\textdegree\fi{} phase-shifted fundamental pulses (zero area) are more efficient than $2\ensuremath{\pi}m$ pulses. Energy conversion efficiencies of 6.5% for third-harmonic (190 nm) and 0.07% for cascade fifth-harmonic (114 nm) pulses are predicted.
The saturation of resonant third-harmonic generation in absorbing and phase-matched high-density systems is investigated theoretically as well as experimentally. It is shown that the saturation is determined by the two-photon absorption [imaginary part of ${\ensuremath{\chi}}_{S}^{(3)}(\ensuremath{\omega})$]. It gives rise to a depletion of the fundamental wave and leads to a change of the level populations and of the effective refractive index destroying the phase matching. This has to be compared with nonresonant systems which are limited by the Kerr effect, the intensity-dependent changes of the refractive index [real part of ${\ensuremath{\chi}}_{S}^{(3)}(\ensuremath{\omega})$]. Optimum conditions for resonant systems are reported.
The dependence of the third harmonic intensity on the medium length under completely phase-matched and resonant conditions is discussed. It is shown that the conversion efficiency in the coherent transient case is expected to exceed that in the steady state case in a long and/or dense medium when the incident light pulse has sufficient energy. The 3S-5S transition of sodium with a 602.3 nm light is studied experimentally as a model system. The efficiency as a function of the incident light frequency and intensity is in agreement with the predictions. By eliminating the phase-mismatching effect, the dependence on the medium density is also determined. It is demonstrated that the efficiency surely increases even in the higher density of sodium.