Vibrational repumping of thallium fluoride

We investigate the B³Π₁(ν_e = 0) ← Χ¹Σ⁺(ν_g = 0) transition in thallium fluoride by imaging the UV fluorescence from the laser excitation of a cryogenic molecular beam. The investigation is motivated by the promise TlF holds for a measurement of the nuclear electric-dipole moment. If cycling losses can be limited to only vibrational losses, our branching fraction measurements suggest that we should be able to scatter about 100 photons from each molecule with a single laser at 271.7 nm [1]. According to these branching ratio measurements, the addition of this single 278.8 nm (ν_g = 2) repump laser could allow cycling of up to 1000 photons if other loss mechanisms can be suppressed. Investigations of this vibrational repumping are reported.

[1] L. R. Hunter, S. K. Peck, A. S. Greenspon, S. Saad Alam, and D. DeMille, Phys. Rev. A 85, 012511 (2012).