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Laboratory for Optical Physics and Engineering [1] W.E. Baylis, J. Chem. Phys (1969) [2] L. Blank, D. E. Weeks, and G. S. Kedziora, J. Chem. Phys. 136, (2012). Theoretically Predicted Activation Barrier In Alkali- Rare Gas Pairs Has Not Been Observed Until Now LiXe Interaction Potentials [1]Calculated potential curves of Rb-Ne molecule [2]
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Laboratory for Optical Physics and Engineering
June 22, 2015
LASER SPECTROSCOPY
OF THE PHOTOASSOCIATION
OF Rb–Ar AND Rb–Xe THERMAL PAIRS
A.E. MIRONOV, WILLIAM GOLDSHLAG, K.T. RAYMOND and J.G. EDEN
Laboratory for Optical Physics and Engineering
Summary
• Alkali-rare gas interactions for R > 4Å have been observed by laser excitation spectroscopy combined with free←free photoassociation.
• Theoretically predicted activation barrier in Rb-Xe
and Rb-Ar A21/2 interaction potential has been
detected.
Laboratory for Optical Physics and Engineering
[1] W.E. Baylis, J. Chem. Phys. 51 2665 (1969)[2] L. Blank, D. E. Weeks, and G. S. Kedziora, J. Chem. Phys. 136, 124315 (2012).
Theoretically Predicted Activation Barrier In Alkali-Rare Gas Pairs Has Not Been Observed Until Now
LiXe Interaction Potentials [1] Calculated potential curves of Rb-Ne molecule [2]
Laboratory for Optical Physics and Engineering
Our New Technique: Wavelength Sweep Across Rb-Xe Activation Barrier In A Threshold-Biased Rb D2 Laser
A2Π1/2 activation barrier at 5.5Å is intentionally exaggerated
1 kT at 200°C
constant λ (bias)
variable λ
signal
Laboratory for Optical Physics and Engineering
Experimental Arrangement
Laboratory for Optical Physics and Engineering
Temporal Evolution of Normalized Pump and ASE Pulse Intensities
Nor
mal
ized
Pul
se a
nd A
SE In
tens
ities
Laboratory for Optical Physics and Engineering
Rb-Xe Excitation Spectrum
[Rb] = 9.2 ∙1014 cm-3, [Xe] = 1.8 ∙1019 cm-3, λ1 = 759.95 nm, Δτ = 9 ns
Laboratory for Optical Physics and Engineering
Rb-Ar Excitation Spectrum
[Rb] = 9.2 ∙1014 cm-3, [Rb] = 1.1 ∙1019 cm-3, λ1 = 755 nm, Δτ = 9 ns
Laboratory for Optical Physics and Engineering
Conclusions
• A new spectroscopic tool has been realized for probing barriers and other weak features in interatomic potentials.
• Barriers in the A2Π1/2 states of Rb-Xe and Rb-Ar have been observed.
Laboratory for Optical Physics and Engineering
Acknowledgement
The support of this work by the High Energy Laser-Joint Technology Office (HEL-JTO) and the U.S. Air Force Office of Scientific Research (J. Luginsland, J. Marshall) under grants FA9550-13-1-0006 and FA9550-14-1-0002, respectively, is gratefully acknowledged.
