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 SPECTROSCOPY OF THE PHOTOASSOCIATION OF Rb-Ar AND Rb-Kr THERMAL PAIRS: STRUCTURE OF THE Rb-RARE GAS A2_1/2 STATE NEAR THE CLASSICAL LIMIT

William Goldshlag

Published Jan 5, 2016• 0 citations
OpenAlex

Abstract

A new laser spectroscopic technique has been demonstrated for examining the structure of alkali--rare gas diatomic electronic states near the classical limit. In two-color experiments, Rb--Ar or Rb--Kr thermal pairs are excited by free$leftarrow$free or bound$leftarrow$free transitions while monitoring the amplified spontaneous emission produced on the Rb D$_1$ or D$_2$ lines. Spectra observed lying within 10 cm$^{-1}$ of the separated atom limit for the A$^{2}Pi_{1/2}$ states of Rb--Ar and Rb--Kr will be presented and discussed.

Related papers

LASER SPECTROSCOPY OF THE PHOTOASSOCIATION OF Rb-Ar AND Rb-Kr THERMAL PAIRS: STRUCTURE OF THE Rb-RARE GAS A2Π1/2 STATE NEAR THE CLASSICAL LIMIT

William Goldshlag, James Gary Eden, Kyle Raymond +1 more

International Symposium on Molecular Spectroscopy (ISMS)•Jun 22, 2015•0 citations

Spectroscopic studies of alkali atom-rare gas systems

Steven J. Davis, Kristin L. Galbally-Kinney, William J. Kessler +1 more

We describe a series of measurements of absorption and laser induced fluorescence on cells that contained cesium and rubidium and a rare gas: He, Ar, Kr, or Xe. These studies showed strong blue wing absorption to the short wavelength side of the alkali atom D2 lines due to collisionally formed Cs- or Rb-rare gas excimers. We also have observed an efficient two photon excitation of higher lying states in Cs and Rb that produces both intense blue emission and IR atomic emission in the 1.3 to 3.8 μm spectral region.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Feb 11, 2010•3 citations

PHOTOASSOCIATION SPECTROSCOPY OF ${^{85}}Rb_{2}$ NEAR ITS DISSOCIATION LIMIT

R. S. Freeland, Ph. W. Courteille, Chin‐Chun Tsai +4 more

We present results which probe the structure of ${^{85}}Rb_{2}$ very near its lowest dissociation limit. To obtain these results, we used two different variations of photoassociation spectroscopy of laser-cooled and trapped ${^{85}}Rb$ atoms. First, we have determined the positions of twelve of the highest vibrational levels of ${^{85}}Rb_{2}$, all bound by less than $0.7 cm^{-1}$, with two-color (free-bound-bound) photoassociation spectroscopy. The levels lie in an energy range for which singlet and triplet states are strongly mixed by the hyperfine interaction. We found that we could accurately describe these states with a novel coupled-channels inverse perturbation analysis. In a second experiment, we have carried out Zeeman-resolved photoassociation spectroscopy. This technique allowed us to probe the energy range in the lowest part of the electronic ground state continuum, which lies between the dissociation limits corresponding to different hyperfine states of the separated atoms. With this method, we have observed a Feshbach scattering resonance in the continuum for the first time, which we find can be tuned to zero energy with a magnetic field.

•Jan 1, 1998•0 citations

Optical Excitation of Metastable Krypton and Photoassociative Spectroscopy of Ultracold RbAr

Grady R. White

n this presentation, we discuss results from two separate bodies of work. In the first, we investigate all-optical excitation methods to produce metastable-state krypton. The high energies required to excite rare gases out of their ground state present a unique challenge in the context of laser experiments. Laser physics work with rare gases often relies on excitation within an RF discharge. All-optical excitation is a promising replacement for RF discharges, avoids problems caused by ion production and may eventually allow for higher efficiencies. We examine three separate methods of all-optical metastable-state production: using an ArF excimer laser, using the third harmonic of the Jefferson Lab free-electron laser (FEL), and using a commercially available UV lamp. In the second body of work, we perform photoassociation spectroscopy in an ultracold, heteronuclear Rb + Ar* system. Photoassociation is a method that may be used to both 1) produce ultracold molecules, and 2) perform high-resolution spectroscopy on excited molecular states. Most work within the field has been performed within all alkali-metal systems. We examine a unique noble gas–alkali system within a dual species magneto-optical trap. We have performed a comprehensive search for evidence of excitation to molecular levels of RbAr. We illuminate atom pairs with a photoassociation laser in a spectral region detuned a few GHz below an atomic asymptote of argon, analogous to previous work in the homo-nuclear argon or krypton systems. We discuss our methodology and findings. We conclude with a discussion of how our results may be applied to future spectroscopic searches

•Jul 3, 2019•0 citations

Photoassociation of krypton and fluorine collision pairs

J. H. Schloss

The photoassociation spectrum of Kr-F collision pairs in thermal equilibrium (293$\sp\circ$K) to KrF(B) has been observed using a laser-induced fluorescence technique with a tunable probe over the wavelength range 219 nm $\leq$ $\lambda$ $\leq$ 250 nm. The spectrum was then analyzed by numerical calculation of the Franck-Condon factors for the bound $\gets$ free transitions. The numerical calculation provided information on the KrF(X) and KrF(B) potential as well as the KrF(B $\to$ X) electronic dipole moment. Saturation intensities for photoassociation produced population were determined at 248 nm for gas mixtures with Kr partial pressures in the range 125 Torr $\leq$ p$\sb{\rm Kr}$ $\leq$ 1000 Torr and 1 Torr of F$\sb2$. Two-photon absorption of Kr/F$\sb2$ mixtures was also observed over the wavelength range 220 nm $\leq$ $\lambda$ $\leq$ 250 nm. The mechanism of the two-photon absorption is determined to be photodissociation of F$\sb2$ followed by photoassociation of non-thermalized Kr-F collision pairs.

•Jan 1, 1989•0 citations

PHOTOASSOCIATION OF ULTRACOLD ATOMS: A NEW TOOL FOR MOLECULAR SPECTROSCOPY

William C. Stwalley

The field of laser cooling and trapping of atoms has had a profound impact on many areas of atomic, molecular and optical science. In particular, ultracold atoms colliding in magneto-optical traps typically have relative kinetic energies of $300\\mu K (\\sim 7 MHz)$, so free-bound absorption lines are as sharp as bound-bound lines. Moreover, because of very long range centrifugal barriers, only a few collisional partial waves are important ($J^{\\prime\\prime} = 0, 1$ and 2 in our work on $^{39}K$). Such photoassociative free-bound absorption allows observation of ``pure long-range molecule'' states ($R_{e} = 28$ and 39 {\\AA} in $^{39}K_{2}$) as well as long-range levels of known short range states with outer classical turning points of $\\sim 20 - 250 {\\AA}$. Such spectra have been observed by ``trap loss'' (decrease in atomic fluorescence), molecular ionization, and fragment ionization. Optical-optical double resonance (OODR), e.g. through the ``Franck-Condon windows'' of the ``pure long-range'' states, produces readily assignable spectra at higher asymptotes as well. Further extensions of ultracold photoassociative spectroscopy and applications to determination of long range potentials, atomic properties, and Bose-Einstein condensate stability will be presented.

•Jan 1, 1998•0 citations
A new laser spectroscopic technique has been demonstrated for examining the structure of alkali--rare gas diatomic electronic states near the classical limit. In two-color experiments, Rb--Ar or Rb--Kr thermal pairs are excited by freeleftarrowleftarrowleftarrowfree or boundleftarrowleftarrowleftarrowfree transitions while monitoring the amplified spontaneous emission produced on the Rb D1_11​ or D2_22​ lines. Spectra observed lying within 10 cm−1^{-1}−1 of the separated atom limit for the A2Pi1/2^{2}Pi_{1/2}2Pi1/2​ states of Rb--Ar and Rb--Kr will be presented and discussed.
We describe a series of measurements of absorption and laser induced fluorescence on cells that contained cesium and rubidium and a rare gas: He, Ar, Kr, or Xe. These studies showed strong blue wing absorption to the short wavelength side of the alkali atom D2 lines due to collisionally formed Cs- or Rb-rare gas excimers. We also have observed an efficient two photon excitation of higher lying states in Cs and Rb that produces both intense blue emission and IR atomic emission in the 1.3 to 3.8 μm spectral region.
PHOTOASSOCIATION SPECTROSCOPY OF 85Rb2{^{85}}Rb_{2}85Rb2​ NEAR ITS DISSOCIATION LIMIT
We present results which probe the structure of 85Rb2{^{85}}Rb_{2}85Rb2​ very near its lowest dissociation limit. To obtain these results, we used two different variations of photoassociation spectroscopy of laser-cooled and trapped 85Rb{^{85}}Rb85Rb atoms. First, we have determined the positions of twelve of the highest vibrational levels of 85Rb2{^{85}}Rb_{2}85Rb2​, all bound by less than 0.7cm−10.7 cm^{-1}0.7cm−1, with two-color (free-bound-bound) photoassociation spectroscopy. The levels lie in an energy range for which singlet and triplet states are strongly mixed by the hyperfine interaction. We found that we could accurately describe these states with a novel coupled-channels inverse perturbation analysis. In a second experiment, we have carried out Zeeman-resolved photoassociation spectroscopy. This technique allowed us to probe the energy range in the lowest part of the electronic ground state continuum, which lies between the dissociation limits corresponding to different hyperfine states of the separated atoms. With this method, we have observed a Feshbach scattering resonance in the continuum for the first time, which we find can be tuned to zero energy with a magnetic field.
n this presentation, we discuss results from two separate bodies of work. In the first, we investigate all-optical excitation methods to produce metastable-state krypton. The high energies required to excite rare gases out of their ground state present a unique challenge in the context of laser experiments. Laser physics work with rare gases often relies on excitation within an RF discharge. All-optical excitation is a promising replacement for RF discharges, avoids problems caused by ion production and may eventually allow for higher efficiencies. We examine three separate methods of all-optical metastable-state production: using an ArF excimer laser, using the third harmonic of the Jefferson Lab free-electron laser (FEL), and using a commercially available UV lamp. In the second body of work, we perform photoassociation spectroscopy in an ultracold, heteronuclear Rb + Ar* system. Photoassociation is a method that may be used to both 1) produce ultracold molecules, and 2) perform high-resolution spectroscopy on excited molecular states. Most work within the field has been performed within all alkali-metal systems. We examine a unique noble gas–alkali system within a dual species magneto-optical trap. We have performed a comprehensive search for evidence of excitation to molecular levels of RbAr. We illuminate atom pairs with a photoassociation laser in a spectral region detuned a few GHz below an atomic asymptote of argon, analogous to previous work in the homo-nuclear argon or krypton systems. We discuss our methodology and findings. We conclude with a discussion of how our results may be applied to future spectroscopic searches
The photoassociation spectrum of Kr-F collision pairs in thermal equilibrium (293$\sp\circ$K) to KrF(B) has been observed using a laser-induced fluorescence technique with a tunable probe over the wavelength range 219 nm ≤\leq≤ λ\lambdaλ ≤\leq≤ 250 nm. The spectrum was then analyzed by numerical calculation of the Franck-Condon factors for the bound ←\gets← free transitions. The numerical calculation provided information on the KrF(X) and KrF(B) potential as well as the KrF(B →\to→ X) electronic dipole moment. Saturation intensities for photoassociation produced population were determined at 248 nm for gas mixtures with Kr partial pressures in the range 125 Torr ≤\leq≤ p$\sb{\rm Kr}$ ≤\leq≤ 1000 Torr and 1 Torr of F$\sb2$. Two-photon absorption of Kr/F$\sb2$ mixtures was also observed over the wavelength range 220 nm ≤\leq≤ λ\lambdaλ ≤\leq≤ 250 nm. The mechanism of the two-photon absorption is determined to be photodissociation of F$\sb2$ followed by photoassociation of non-thermalized Kr-F collision pairs.
The field of laser cooling and trapping of atoms has had a profound impact on many areas of atomic, molecular and optical science. In particular, ultracold atoms colliding in magneto-optical traps typically have relative kinetic energies of 300muK(sim7MHz)300\\mu K (\\sim 7 MHz)300muK(sim7MHz), so free-bound absorption lines are as sharp as bound-bound lines. Moreover, because of very long range centrifugal barriers, only a few collisional partial waves are important (Jprimeprime=0,1J^{\\prime\\prime} = 0, 1Jprimeprime=0,1 and 2 in our work on 39K^{39}K39K). Such photoassociative free-bound absorption allows observation of ``pure long-range molecule'' states (Re=28R_{e} = 28Re​=28 and 39 {\\AA} in 39K2^{39}K_{2}39K2​) as well as long-range levels of known short range states with outer classical turning points of sim20−250AA\\sim 20 - 250 {\\AA}sim20−250AA. Such spectra have been observed by ``trap loss'' (decrease in atomic fluorescence), molecular ionization, and fragment ionization. Optical-optical double resonance (OODR), e.g. through the ``Franck-Condon windows'' of the ``pure long-range'' states, produces readily assignable spectra at higher asymptotes as well. Further extensions of ultracold photoassociative spectroscopy and applications to determination of long range potentials, atomic properties, and Bose-Einstein condensate stability will be presented.