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

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Coherent spectral repers: contrast, steepness, and slow molecule detection

L. S. Vasilenko, Н. Н. Рубцова, Хворостов Евгений Борисович

Published Sep 26, 1997• 0 citations
Publisher

Abstract

The contrast and steepness of spectral repers, detected by two nonlinear Doppler free techniques -- photon echo in standing waves (PESW) and saturated absorption spectroscopy (SAS) -- are investigated at 0 yields 1 (nu) 3 P(33) A21 SF6 transition for identical experimental conditions (over gas pressure and exciting beams geometry) versus intensity of CO2 laser radiation. S/N advantage of PESW technique as compared to SAS method is demonstrated. The increasing role of slow molecules in generation of photon echo response at elevated time delays between exciting pulses manifests itself experimentally in slowing down the photon echo decay rate.

DOI
10.1117/12.287700

Related papers

Spectral repers and slow-molecule detection using the photon echo technique and its modifications

L. S. Vasilenko, Н. Н. Рубцова, Хворостов Евгений Борисович

The contrast and steepness of spectral repers, detected by two nonlinear Doppler free techniques -- photon echo in standing waves (PESW) and saturated absorption spectroscopy (SAS) -- are investigated at 0 yields 1 (nu) 3 P(33) A1/2 SF6 transition for identical experimental conditions versus intensity of CO2 laser radiation. S/N advantage of PESW technique as compared to SAS method is demonstrated. The increasing role of slow molecules in generation of photon echo response at elevated time delays between exciting pulses manifests itself experimentally in slowing down the photon echo decay rate.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Oct 21, 1998•0 citations

Nonlinear Doppler-free spectroscopy of atoms near a surface

Pierre Simoneau, S. Le Boiteux, C. De Araujo +2 more

Up to now, Doppler-free nonlinear spectroscopy has been applied to atoms inside a gas medium (volume spectroscopy). We have extended these methods to atoms in the vicinity of a surface. The basic principle consists of monitoring reflectivity changes produced when a laser beam, incident on a glass–vapor interface, is brought into resonance with an atomic transition. For Doppler-free spectroscopy, two counterpropagating beams are used to operate velocity selection. If these two beams are under normal incidence in the glass—velocity selection perpendicular to the surface—one observes saturated dispersion (selective reflection sensitive to the real index). For incidence angles in the glass (prism) larger than the critical angle (total internal reflection), a standing evanescent wave is produced in the gas (velocity selection along the surface), and saturated absorption is detected. Experimental demonstration was performed on the Na resonance line; high sensitivity (10−4 relative reflectivity change) and spectral resolution as good as 20 MHz were obtained. The main limitation to better resolution comes from the short atomic transit time in the evanescent wave (typical extension ~λ). Relevant applications of these techniques should also concern the diagnostics of optically thick media, as analysis of interaction between gas-phase atoms and the surface, notably atom–wall collisions, and modification of the spontaneous emission characteristics.

International Laser Science Conference•Jan 1, 1986•0 citations

Coherent transients generated at molecular levels dressed by electromagnetic field

Н. Н. Рубцова, T. P. Konstantinova

Free polarization decay and photon echo were studied experimentally in polar gas 13CH3F at the transition R(4,3) of vibrational mode 0 yields 1 (nu) 3 by Stark switching of molecular levels under irradiation by CW CO2 laser at 9P(32) line. Application of 4.5 mcs pulse to the Stark electrodes inside the gas cell allows to detect the free polarization decay signal, combined with the optical nutation. The sign of the signal corresponds to the increase of absorption in the limit of low intensity (not over 0.01 W/cm2) saturating radiation. Exciting intensity growth till the level of 6.0 W/cm2 implies decrease of signal absolute value, till the change of its sign, while the oscillation of the free polarization decay signal reveals remarkable frequency shift. Such behavior is attributed to the combined action of the dynamic Stark effect of CW radiation field and the levels splitting by the Stark voltage. Two shorter (of about 0.1 and 0.2 mcs) Stark pulses, applied to the gas, generate the photon echo signals detected by the same heterodyne technique. The study of the variations of photon echo parameters versus exciting radiation intensity is in progress.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 30, 2002•4 citations

Coherent transients in molecular gases

Н. Н. Рубцова

Coherent transient phenomena can be generated by the abrupt changes of parameters either of the electromagnetic field or of the matter. Comparative analysis of these two approaches, made on the base of experimental research in molecular gases SF6, 15NH3, HFCO and 13CH3F, excited by the radiation of CW CO2 and 13CO2 lasers, is presented. The first approach of photon echo (and its modifications) generation, based on electro-optic pulses formation from the resonant CW exciting radiation, has proven to be successful for intense infrared molecular transitions. The coherent responses are sufficiently powerful to be applied in high resolution spectroscopy, the spectral markers creation ,and molecular collisions investigations. However, this technique is not very effective for the free polarization decay investigations. Another approach based on the Stark switching molecular levels of polar gas, irradiated by CW laser, was demonstrated for free polarization decay and photon echo generation in 13CH3F. Free polarization decay has shown the pronounced frequency shift because of dynamic Stark effect in the CW radiation field. This specific feature of coherent transients, created by Stark switching, limits the high resolution spectroscopy by the low intensity range of exciting radiation. From other viewpoint, it gives unique possibility to investigate coherent transients generated at the dressed molecular levels.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 30, 2002•4 citations

Detection peculiarities of coherent transients generated in molecular gas by Stark switching

Н. Н. Рубцова, T. P. Konstantinova, Хворостов Евгений Борисович +2 more

Free polarization decay and photon echo were detected as heterodyne signals in the weak component of radiation, polarized at right angle to the principal part of exciting radiation. Coherent responses were generated in 13CH3F gas by Stark switching of molecular levels in a gas excited by CW CO2 laser radiation at 9P (32) line. The specific features of this technique in comparison with the conventional Stark switching method of coherent transients generation is considered.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Nov 15, 2001•0 citations

Nonlinear spectroscopy of rubidium: an undergraduate experiment

V. Jacques, B Hingant, A. Allafort +2 more

In this paper, we describe two complementary nonlinear spectroscopy methods which both allow one to achieve Doppler-free spectra of atomic gases. First, saturated absorption spectroscopy is used to investigate the structure of the 5S 1/2 → 5P 3/2 transition in rubidium. Using a slightly modified experimental setup, Doppler-free two-photon absorption spectroscopy is then performed on the 5S 1/2 → 5D 5/2 transition in rubidium, leading to accurate measurements of the hyperfine structure of the 5D 5/2 energy level. In addition, electric dipole selection rules of the two-photon transition are investigated, first by modifying the polarization of the excitation laser, and then by measuring two-photon absorption spectra when a magnetic field is applied close to the rubidium vapour. All experiments are performed with the same grating-feedback laser diode, providing an opportunity to compare different high-resolution spectroscopy methods using a single experimental setup. Such experiments may acquaint students with quantum mechanics selection rules, atomic spectra and Zeeman effect.

arXiv:0902.3115•European Journal of Physics•Jul 8, 2009•22 citations
The contrast and steepness of spectral repers, detected by two nonlinear Doppler free techniques -- photon echo in standing waves (PESW) and saturated absorption spectroscopy (SAS) -- are investigated at 0 yields 1 (nu) 3 P(33) A21 SF6 transition for identical experimental conditions (over gas pressure and exciting beams geometry) versus intensity of CO2 laser radiation. S/N advantage of PESW technique as compared to SAS method is demonstrated. The increasing role of slow molecules in generation of photon echo response at elevated time delays between exciting pulses manifests itself experimentally in slowing down the photon echo decay rate.
The contrast and steepness of spectral repers, detected by two nonlinear Doppler free techniques -- photon echo in standing waves (PESW) and saturated absorption spectroscopy (SAS) -- are investigated at 0 yields 1 (nu) 3 P(33) A1/2 SF6 transition for identical experimental conditions versus intensity of CO2 laser radiation. S/N advantage of PESW technique as compared to SAS method is demonstrated. The increasing role of slow molecules in generation of photon echo response at elevated time delays between exciting pulses manifests itself experimentally in slowing down the photon echo decay rate.
Up to now, Doppler-free nonlinear spectroscopy has been applied to atoms inside a gas medium (volume spectroscopy). We have extended these methods to atoms in the vicinity of a surface. The basic principle consists of monitoring reflectivity changes produced when a laser beam, incident on a glass–vapor interface, is brought into resonance with an atomic transition. For Doppler-free spectroscopy, two counterpropagating beams are used to operate velocity selection. If these two beams are under normal incidence in the glass—velocity selection perpendicular to the surface—one observes saturated dispersion (selective reflection sensitive to the real index). For incidence angles in the glass (prism) larger than the critical angle (total internal reflection), a standing evanescent wave is produced in the gas (velocity selection along the surface), and saturated absorption is detected. Experimental demonstration was performed on the Na resonance line; high sensitivity (10−4 relative reflectivity change) and spectral resolution as good as 20 MHz were obtained. The main limitation to better resolution comes from the short atomic transit time in the evanescent wave (typical extension ~λ). Relevant applications of these techniques should also concern the diagnostics of optically thick media, as analysis of interaction between gas-phase atoms and the surface, notably atom–wall collisions, and modification of the spontaneous emission characteristics.
Free polarization decay and photon echo were studied experimentally in polar gas 13CH3F at the transition R(4,3) of vibrational mode 0 yields 1 (nu) 3 by Stark switching of molecular levels under irradiation by CW CO2 laser at 9P(32) line. Application of 4.5 mcs pulse to the Stark electrodes inside the gas cell allows to detect the free polarization decay signal, combined with the optical nutation. The sign of the signal corresponds to the increase of absorption in the limit of low intensity (not over 0.01 W/cm2) saturating radiation. Exciting intensity growth till the level of 6.0 W/cm2 implies decrease of signal absolute value, till the change of its sign, while the oscillation of the free polarization decay signal reveals remarkable frequency shift. Such behavior is attributed to the combined action of the dynamic Stark effect of CW radiation field and the levels splitting by the Stark voltage. Two shorter (of about 0.1 and 0.2 mcs) Stark pulses, applied to the gas, generate the photon echo signals detected by the same heterodyne technique. The study of the variations of photon echo parameters versus exciting radiation intensity is in progress.
Coherent transient phenomena can be generated by the abrupt changes of parameters either of the electromagnetic field or of the matter. Comparative analysis of these two approaches, made on the base of experimental research in molecular gases SF6, 15NH3, HFCO and 13CH3F, excited by the radiation of CW CO2 and 13CO2 lasers, is presented. The first approach of photon echo (and its modifications) generation, based on electro-optic pulses formation from the resonant CW exciting radiation, has proven to be successful for intense infrared molecular transitions. The coherent responses are sufficiently powerful to be applied in high resolution spectroscopy, the spectral markers creation ,and molecular collisions investigations. However, this technique is not very effective for the free polarization decay investigations. Another approach based on the Stark switching molecular levels of polar gas, irradiated by CW laser, was demonstrated for free polarization decay and photon echo generation in 13CH3F. Free polarization decay has shown the pronounced frequency shift because of dynamic Stark effect in the CW radiation field. This specific feature of coherent transients, created by Stark switching, limits the high resolution spectroscopy by the low intensity range of exciting radiation. From other viewpoint, it gives unique possibility to investigate coherent transients generated at the dressed molecular levels.
In this paper, we describe two complementary nonlinear spectroscopy methods which both allow one to achieve Doppler-free spectra of atomic gases. First, saturated absorption spectroscopy is used to investigate the structure of the 5S 1/2 → 5P 3/2 transition in rubidium. Using a slightly modified experimental setup, Doppler-free two-photon absorption spectroscopy is then performed on the 5S 1/2 → 5D 5/2 transition in rubidium, leading to accurate measurements of the hyperfine structure of the 5D 5/2 energy level. In addition, electric dipole selection rules of the two-photon transition are investigated, first by modifying the polarization of the excitation laser, and then by measuring two-photon absorption spectra when a magnetic field is applied close to the rubidium vapour. All experiments are performed with the same grating-feedback laser diode, providing an opportunity to compare different high-resolution spectroscopy methods using a single experimental setup. Such experiments may acquaint students with quantum mechanics selection rules, atomic spectra and Zeeman effect.