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

Physical Review A

Anomalous two-photon spectral features in warm rubidium vapor

Christopher Perrella, P. S. Light, Thomas J. Milburn, D. Kielpinski, Thomas M. Stace, Andre Nicholas Luiten

Published Sep 1, 2016• 0 citations
Publisher

Abstract

We report observation of anomalous fluorescence spectral features in the environs of a two-photon transition in a rubidium vapor when excited with two different wavelength lasers that are both counterpropagating through the vapor. These features are characterized by an unusual trade-off between the detunings of the driving fields. Three different hypothetical processes are presented to explain the observed spectra: a simultaneous three-atom and four-photon collision, a four-photon excitation involving a light field produced via amplified spontaneous emission, and population pumping perturbing the expected steady-state spectra. Numerical modeling of each hypothetical process is presented, supporting the population pumping process as the most plausible mechanism.

DOI
10.1103/physreva.94.033403

Related papers

Amplified spontaneous emission at 523 μm in two-photon excited rubidium vapor

A. M. Akulshin, Nafia Rahaman, Sergey A. Suslov +1 more

Population inversion on the 5D5/2−6P3/2 transition in rubidium atoms produced by cw laser excitation at different wavelengths has been analyzed by comparing the generated mid-infrared radiation at 5.23 μm originating from amplified spontaneous emission (ASE) and isotropic blue fluorescence at 420 nm. Using a novel method for detection of two-photon excitation via ASE, we have observed directional co- and counter-propagating emission at 5.23 μm. Evidence of a threshold-like characteristic is found in the ASE dependences on laser detuning and Rb number density. The power dependences of the backward- and forward-directed emission can be very similar; however, their spectral dependences are not identical. A new type of temporally and spatially coherent radiation is suggested.

arXiv:1701.00232•Journal of the Optical Society of America B•Nov 7, 2017•22 citations

Observation of narrow fluorescence from doubly driven four-level atoms at room temperature

U. K Khan, J Sebastian, N Kamaraju +3 more

Unusually narrow spectral features are seen in fluorescence peaks from 85 Rb atoms under the action of two driving laser fields that are in a three-dimensional molasses configuration. One of the lasers, L1, is held at a fixed detuning from the "cooling" transition, while the other, L2, is scanned across the "repumping" transitions. The fluorescence peaks are split into symmetric pairs, with the separation within a pair increasing with the detuning of the L1 laser. For large detunings, additional small peaks are seen. A simple model is proposed to explain these experimental observations.

arXiv:cond-mat/0401280•Europhysics Letters (EPL)•Jul 1, 2004•5 citations

EXCITATION ENERGY TRANSFER BY COLLISIONS BETWEEN EXCITED RUBIDIUM ATOMS

Jin Wang, Zhengfa Hu, Deng-Yu Zhang +2 more

This paper reports the experimental observation of the excitation energy transfer to higher states by collisions between two rubidium atoms excited to a specific state by a CW single mode laser. An obvious competition has been observed between the channel of transition to the ground state by spontaneous emission, and that to higher excited states by collisions of two excited atoms. Formation rates of the high excited states with different laser power, atomic vapor temperature and laser detuning have been measured. A proposed mechanism well explained the experimental result.

Acta Physica Sinica•Jan 1, 1998•1 citation

Telecom-wavelength spectra of a Rydberg state in a hot vapor

Wenfang Li, Jinjin Du, Mark Lam +1 more

We study telecom-wavelength spectra of a Rydberg state in an atomic vapor with a three-photon excitation scheme. Two lasers of 780 nm and 776 nm are used to pump rubidium-85 atoms in a vapor cell to the 5 D 5/2 state, from which a probe beam of 1292 nm in the O-band telecommunication wavelength drives a transition to the 21 F 7/2 Rydberg state. We investigate the probe spectra over the power of pump lasers. The simulation based on a 4-level theoretical model captures the main features of the experimental results. This spectroscopic study paves the way for future experiments of making a direct link between fiber optics and radio transmission via Rydberg atoms.

arXiv:2209.08927•Optics Letters•Aug 8, 2022•7 citations

Two-photon resonant forward four-wave mixing in rubidium vapor involving Rydberg states

Natalia R. de Melo, S. S. Vianna

We report on observations of four-wave mixing in rubidium vapor via two-photon resonant excitation with nd and (n+2)s states, for n=14–20. The intensity of the generated beam is studied in a collinear configuration, and the results are consistent with the predictions of a theoretical model based on the semiclassical Maxwell–Bloch equations, considering interference effects associated with multiple excitation pathways and with internally generated fields. We have also observed spectral broadening of the two-photon resonant lines, which is well described by a linear dependence on atomic density, in accordance with collision-induced broadening.

Journal of the Optical Society of America B•Jun 27, 2014•18 citations

Stimulated Raman gain in a Λ-type atomic system with doubly excited transitions

Jason L. Bowie, J. C. Garrison, R. Y. Chiao

Measurements of stimulated Raman gain in rubidium vapor are made and compared with a detailed model. Amplification of a weak probe laser is observed in a \ensuremath{\Lambda}-type three-level system that is driven by a strong cw coupling laser. The intensity of the coupling laser is sufficiently strong that it both optically pumps the atomic levels, causing a population inversion in the ground-state hyperfine levels, and drives the stimulated Raman process producing gain. A theory that models all aspects of the gain mechanism is presented. The model includes all interactions between the external fields and the atomic transitions, including those processes that involve multiple fields interacting with the same transition. Numerical calculations are compared with gain measurements made at several coupling laser intensities and detunings from the $D1$ line in ${}^{85}\mathrm{Rb}.$

Physical Review A•Apr 14, 2000•9 citations
We report observation of anomalous fluorescence spectral features in the environs of a two-photon transition in a rubidium vapor when excited with two different wavelength lasers that are both counterpropagating through the vapor. These features are characterized by an unusual trade-off between the detunings of the driving fields. Three different hypothetical processes are presented to explain the observed spectra: a simultaneous three-atom and four-photon collision, a four-photon excitation involving a light field produced via amplified spontaneous emission, and population pumping perturbing the expected steady-state spectra. Numerical modeling of each hypothetical process is presented, supporting the population pumping process as the most plausible mechanism.
Population inversion on the 5D5/2−6P3/2 transition in rubidium atoms produced by cw laser excitation at different wavelengths has been analyzed by comparing the generated mid-infrared radiation at 5.23 μm originating from amplified spontaneous emission (ASE) and isotropic blue fluorescence at 420 nm. Using a novel method for detection of two-photon excitation via ASE, we have observed directional co- and counter-propagating emission at 5.23 μm. Evidence of a threshold-like characteristic is found in the ASE dependences on laser detuning and Rb number density. The power dependences of the backward- and forward-directed emission can be very similar; however, their spectral dependences are not identical. A new type of temporally and spatially coherent radiation is suggested.
Unusually narrow spectral features are seen in fluorescence peaks from 85 Rb atoms under the action of two driving laser fields that are in a three-dimensional molasses configuration. One of the lasers, L1, is held at a fixed detuning from the "cooling" transition, while the other, L2, is scanned across the "repumping" transitions. The fluorescence peaks are split into symmetric pairs, with the separation within a pair increasing with the detuning of the L1 laser. For large detunings, additional small peaks are seen. A simple model is proposed to explain these experimental observations.
This paper reports the experimental observation of the excitation energy transfer to higher states by collisions between two rubidium atoms excited to a specific state by a CW single mode laser. An obvious competition has been observed between the channel of transition to the ground state by spontaneous emission, and that to higher excited states by collisions of two excited atoms. Formation rates of the high excited states with different laser power, atomic vapor temperature and laser detuning have been measured. A proposed mechanism well explained the experimental result.
We study telecom-wavelength spectra of a Rydberg state in an atomic vapor with a three-photon excitation scheme. Two lasers of 780 nm and 776 nm are used to pump rubidium-85 atoms in a vapor cell to the 5 D 5/2 state, from which a probe beam of 1292 nm in the O-band telecommunication wavelength drives a transition to the 21 F 7/2 Rydberg state. We investigate the probe spectra over the power of pump lasers. The simulation based on a 4-level theoretical model captures the main features of the experimental results. This spectroscopic study paves the way for future experiments of making a direct link between fiber optics and radio transmission via Rydberg atoms.
We report on observations of four-wave mixing in rubidium vapor via two-photon resonant excitation with nd and (n+2)s states, for n=14–20. The intensity of the generated beam is studied in a collinear configuration, and the results are consistent with the predictions of a theoretical model based on the semiclassical Maxwell–Bloch equations, considering interference effects associated with multiple excitation pathways and with internally generated fields. We have also observed spectral broadening of the two-photon resonant lines, which is well described by a linear dependence on atomic density, in accordance with collision-induced broadening.
Measurements of stimulated Raman gain in rubidium vapor are made and compared with a detailed model. Amplification of a weak probe laser is observed in a \ensuremath{\Lambda}-type three-level system that is driven by a strong cw coupling laser. The intensity of the coupling laser is sufficiently strong that it both optically pumps the atomic levels, causing a population inversion in the ground-state hyperfine levels, and drives the stimulated Raman process producing gain. A theory that models all aspects of the gain mechanism is presented. The model includes all interactions between the external fields and the atomic transitions, including those processes that involve multiple fields interacting with the same transition. Numerical calculations are compared with gain measurements made at several coupling laser intensities and detunings from the D1D1D1 line in 85Rb.{}^{85}\mathrm{Rb}.85Rb.