1. 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

2. Laboratory for Optical Physics and Engineering Summary

3. 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]

4. Laboratory for Optical Physics and Engineering Our New Technique: Wavelength Sweep Across Rb-Xe Activation Barrier In A Threshold-Biased Rb D 2 Laser A 2 Π 1/2 activation barrier at 5.5Å is intentionally exaggerated 1 kT at 200°C constant λ (bias) variable λ signal

5. Laboratory for Optical Physics and Engineering Experimental Arrangement

6. Laboratory for Optical Physics and Engineering Temporal Evolution of Normalized Pump and ASE Pulse Intensities Normalized Pulse and ASE Intensities

7. Laboratory for Optical Physics and Engineering Rb-Xe Excitation Spectrum [Rb] = 9.2 ∙10 14 cm -3, [Xe] = 1.8 ∙10 19 cm -3, λ 1 = 759.95 nm, Δτ = 9 ns

8. Laboratory for Optical Physics and Engineering Rb-Ar Excitation Spectrum [Rb] = 9.2 ∙10 14 cm -3, [Rb] = 1.1 ∙10 19 cm -3, λ 1 = 755 nm, Δτ = 9 ns

9. 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 A 2 Π 1/2 states of Rb-Xe and Rb-Ar have been observed.

10. 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.