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

5S−5D two-photon transition in rubidium vapor at high densities

K. Hassanin, P. Federsel, Florian Karlewski, Claus Zimmermann

Published Apr 5, 2023• 10 citations
Publisher

Abstract

The rubidium $5S\text{\ensuremath{-}}5D$ Doppler-free two-photon transition has been observed in a thermal vapor cell by detecting the infrared radiation emitted during the decay from the $5D$ excited level to the $5P$ intermediate level. Different to the usual detection scheme based on blue light emission this approach does not suffer from reabsorption and still works at high densities. This not only allows for a dramatically enhanced detectable emission rate but also for investigating collisional effects such as collisional broadening and collisional energy transfer. Furthermore, we observe a yet unknown temperature dependence of the resonance linewidth for transitions into the states of the $5{D}_{\text{5/2}}$ level. Consequences for the design of an optical Rb-frequency standard are discussed.

DOI
10.1103/physreva.107.043104

Related papers

Two-Photon Transitions of 85 Rb 5 D 5/2 State by Using an Optical Frequency Comb and a Continuous-Wave Laser

Cao Shu-Kai, Peng-Rui Fan, Zhang Yi-Chi +3 more

A high-resolution two-photon spectrum of 5S 1/2 → 5P 3/2 → 5D 5/2 transitions in a thermal 85 Rb vapor cell is presented by using an optical frequency comb and a cw laser. The fluorescence of 6P 3/2 → 5S 1/2 spontaneous emission is detected when the cw laser frequency is scanned from the 5S 1/2 ground state to 5P 3/2 hyperfine levels and the optical frequency comb repetition rate is fixed. The hyperfine splittings (F f = 2–5) of the 5D 5/2 excited state are well resolved. The dependences of fluorescence intensities on the cw laser intensity and temperature of 85 Rb vapor cell are studied, respectively. The experimental results are in good agreement with the theoretical analyses.

Chinese Physics Letters•Feb 1, 2016•0 citations

Laser-Induced Population Changes of 5P and 5D Levels in Rubidium Vapor

Wang Shu-ying

Enhancement and reduction of the fluorescence intensity in Rb atomic vapor are observed. The reduction is due to a depopulation of the 5P - {3/2 } state upon illumination of a Rb vapor cell with light corresponding to the 5P - {3/2 }→5D - {5/2 } transition. Collisional transfer of the 5D - {5/2 } atoms to the 5D - {3/2 } state, followed by radiative decay to the 5P - {1/2 } state, creates an increase in the population of the 5P - {1/2 } state. The increase in the excited state population results in an increase in the fluorescence intensity of the 5P - {1/2 }→5S - {1/2 } transition. The laser-induced population changes are monitored by the decrease or increase of the corresponding fluorescence signals. Using the steady-state rate equations, the rate constants for the stimulated emission(i.e., 5D - {5/2 }→5P - {3/2 }) is 2.0×10 +8s + {-1 }. The cross section for the fine-structure changing collision(i.e., 5D - {5/2 }→5D - {3/2 }) is 6.4×10 + {-14 }cm +2.

Shinjang dashösi ilmiy jurnili•Jan 1, 2005•0 citations

Doppler-free two-photon resonances for atom detection and sum frequency stabilization

A. M. Akulshin, B. V. Hall, V Ivannikov +2 more

We investigate the excitation of the 5D_{5/2} level in Rb atoms using counter-propagating laser beams, which are nearly resonant to the one-photon 5S_{1/2} - 5P_{3/2} and 5P_{3/2} - 5D_{5/2} transitions, ensuring that a sum of the optical frequencies corresponds to the 5S_{1/2} - 5D_{5/2} transition. The excitation produced by two-photon and step-wise processes is detected via spontaneously emitted fluorescence at 420 nm arising from the 6P_{3/2} - 5S_{1/2} transition. The dependences of blue fluorescence intensity on atomic density and laser detuning from the intermediate 5P_{3/2} level have been investigated. The sensitivity of the frequency detuned bi-chromatic scheme for atom detection has been estimated. A novel method for sum frequency stabilization of two free-running lasers has been suggested and implemented using two-photon Doppler-free fluorescence and polarization resonances.

arXiv:1106.0959•Journal of Physics B Atomic Molecular and Optical Physics•Oct 18, 2011•24 citations

Velocity-selective double resonance in Doppler-broadened rubidium vapor

Nataša Vujičić, Ticijana Ban, Gordana Kregar +2 more

We study resonantly enhanced cascaded two-photon transitions in Doppler-broadened rubidium vapor, induced by an optical frequency comb. Cascaded two-step excitation of atoms from the ground state 5$S$${}_{1/2}$ to the final 5$D$${}_{5/2}$ state via an intermediate 5$P$${}_{3/2}$ state as well as the influence of the frequency comb repetition rate on the two-photon fluorescence signal have been investigated. It is shown that the careful choice of ${f}_{R}$ leads to enhancement of the two-photon signal with considerable increase of the final $5{D}_{5/2}$-state population due to velocity-selective double resonance. Since the double-resonance condition for two different rubidium isotopes is fulfilled for different ${f}_{R}$, the possibility of isotope-selective two-photon excitation is explored. The dependence of the two-photon signal on external magnetic field values and different repetition rates of the optical frequency comb is also investigated.

Physical Review A•Jan 31, 2013•14 citations

Six-Wave Mixing Near-Infrared Emissions in Rubidium Vapor

Yao-Ju Chan, Wei‐Tzou Luh

During two-photon excitation studies of rubidium vapor, in addition to Rb near-infrared atomic transitions, we have observed several stimulated near-infrared emissions. For the 5S-5D two-photon allowed excitation we observed emissions near 1.325, 1.369, 1.373, 1.477, 1.533 and 1.537 pm, and for the Rb 5S-7s two-photon allowed excitation we observed emissions near 1.330, 1.395, 1.432, 1.484, 1.564 and 1.613 pm. The eight emissions, near 1.325, 1.330, 1.369, 1.395, 1.477, 1.484, 1.533 and 1.564 pm are interpreted as axially phase-matched six-wave mixing emissions, while the other four emissions, near 1.373, 1.432, 1.537 and 1.613 pm, are interpreted as angle phasematched six-wave mixing emissions. Temperature (or number density)-dependent evclution curves of some of the above six-wave mixing emissions have also been measured. The results reveal that different mixing processes occur at different rubidium number densities.

Chinese Journal of Physics•Jun 1, 1995•2 citations

Heterodyne Doppler-free two-photon absorption and dispersion in rubidium vapour

Daniel Bloch, M. Ducloy, E. Giacobino

Heterodyne Doppler-free spectroscopy, previously demonstrated on single-photon resonances (heterodyne saturation spectroscopy), has been extended to two-photon transitions in rubidium (5S-5D and 5S-7S). It provides a simple method of observing the two-photon dispersion lineshape directly. The noticeable sensitivity of this absorption technique, which has been used for an optical measurement of the hyperfine structure of the 5D level, is discussed in comparison with that currently obtained in two-photon-induced fluorescence.

Journal of Physics B Atomic and Molecular Physics•Dec 28, 1981•10 citations
The rubidium 5S\ensuremath-5D5S\text{\ensuremath{-}}5D5S\ensuremath-5D Doppler-free two-photon transition has been observed in a thermal vapor cell by detecting the infrared radiation emitted during the decay from the 5D5D5D excited level to the 5P5P5P intermediate level. Different to the usual detection scheme based on blue light emission this approach does not suffer from reabsorption and still works at high densities. This not only allows for a dramatically enhanced detectable emission rate but also for investigating collisional effects such as collisional broadening and collisional energy transfer. Furthermore, we observe a yet unknown temperature dependence of the resonance linewidth for transitions into the states of the 5D5/25{D}_{\text{5/2}}5D5/2​ level. Consequences for the design of an optical Rb-frequency standard are discussed.
A high-resolution two-photon spectrum of 5S 1/2 → 5P 3/2 → 5D 5/2 transitions in a thermal 85 Rb vapor cell is presented by using an optical frequency comb and a cw laser. The fluorescence of 6P 3/2 → 5S 1/2 spontaneous emission is detected when the cw laser frequency is scanned from the 5S 1/2 ground state to 5P 3/2 hyperfine levels and the optical frequency comb repetition rate is fixed. The hyperfine splittings (F f = 2–5) of the 5D 5/2 excited state are well resolved. The dependences of fluorescence intensities on the cw laser intensity and temperature of 85 Rb vapor cell are studied, respectively. The experimental results are in good agreement with the theoretical analyses.
Enhancement and reduction of the fluorescence intensity in Rb atomic vapor are observed. The reduction is due to a depopulation of the 5P - {3/2 } state upon illumination of a Rb vapor cell with light corresponding to the 5P - {3/2 }→5D - {5/2 } transition. Collisional transfer of the 5D - {5/2 } atoms to the 5D - {3/2 } state, followed by radiative decay to the 5P - {1/2 } state, creates an increase in the population of the 5P - {1/2 } state. The increase in the excited state population results in an increase in the fluorescence intensity of the 5P - {1/2 }→5S - {1/2 } transition. The laser-induced population changes are monitored by the decrease or increase of the corresponding fluorescence signals. Using the steady-state rate equations, the rate constants for the stimulated emission(i.e., 5D - {5/2 }→5P - {3/2 }) is 2.0×10 +8s + {-1 }. The cross section for the fine-structure changing collision(i.e., 5D - {5/2 }→5D - {3/2 }) is 6.4×10 + {-14 }cm +2.
We investigate the excitation of the 5D_{5/2} level in Rb atoms using counter-propagating laser beams, which are nearly resonant to the one-photon 5S_{1/2} - 5P_{3/2} and 5P_{3/2} - 5D_{5/2} transitions, ensuring that a sum of the optical frequencies corresponds to the 5S_{1/2} - 5D_{5/2} transition. The excitation produced by two-photon and step-wise processes is detected via spontaneously emitted fluorescence at 420 nm arising from the 6P_{3/2} - 5S_{1/2} transition. The dependences of blue fluorescence intensity on atomic density and laser detuning from the intermediate 5P_{3/2} level have been investigated. The sensitivity of the frequency detuned bi-chromatic scheme for atom detection has been estimated. A novel method for sum frequency stabilization of two free-running lasers has been suggested and implemented using two-photon Doppler-free fluorescence and polarization resonances.
We study resonantly enhanced cascaded two-photon transitions in Doppler-broadened rubidium vapor, induced by an optical frequency comb. Cascaded two-step excitation of atoms from the ground state 5SSS1/2{}_{1/2}1/2​ to the final 5DDD5/2{}_{5/2}5/2​ state via an intermediate 5PPP3/2{}_{3/2}3/2​ state as well as the influence of the frequency comb repetition rate on the two-photon fluorescence signal have been investigated. It is shown that the careful choice of fR{f}_{R}fR​ leads to enhancement of the two-photon signal with considerable increase of the final 5D5/25{D}_{5/2}5D5/2​-state population due to velocity-selective double resonance. Since the double-resonance condition for two different rubidium isotopes is fulfilled for different fR{f}_{R}fR​, the possibility of isotope-selective two-photon excitation is explored. The dependence of the two-photon signal on external magnetic field values and different repetition rates of the optical frequency comb is also investigated.
During two-photon excitation studies of rubidium vapor, in addition to Rb near-infrared atomic transitions, we have observed several stimulated near-infrared emissions. For the 5S-5D two-photon allowed excitation we observed emissions near 1.325, 1.369, 1.373, 1.477, 1.533 and 1.537 pm, and for the Rb 5S-7s two-photon allowed excitation we observed emissions near 1.330, 1.395, 1.432, 1.484, 1.564 and 1.613 pm. The eight emissions, near 1.325, 1.330, 1.369, 1.395, 1.477, 1.484, 1.533 and 1.564 pm are interpreted as axially phase-matched six-wave mixing emissions, while the other four emissions, near 1.373, 1.432, 1.537 and 1.613 pm, are interpreted as angle phasematched six-wave mixing emissions. Temperature (or number density)-dependent evclution curves of some of the above six-wave mixing emissions have also been measured. The results reveal that different mixing processes occur at different rubidium number densities.
Heterodyne Doppler-free spectroscopy, previously demonstrated on single-photon resonances (heterodyne saturation spectroscopy), has been extended to two-photon transitions in rubidium (5S-5D and 5S-7S). It provides a simple method of observing the two-photon dispersion lineshape directly. The noticeable sensitivity of this absorption technique, which has been used for an optical measurement of the hyperfine structure of the 5D level, is discussed in comparison with that currently obtained in two-photon-induced fluorescence.