Spectroscopic characterization of the a3Π state of aluminum monofluoride
| Autor: | N. Walter, M. Doppelbauer, S. Marx, J. Seifert, X. Liu, J. Pérez-Ríos, B. G. Sartakov, S. Truppe, G. Meijer |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | The Journal of Chemical Physics |
| ISSN: | 1089-7690 0021-9606 |
| DOI: | 10.1063/5.0082601 |
| Popis: | Spectroscopic studies of aluminum monofluoride (AlF) have revealed its highly favorable properties for direct laser cooling. All $Q$ lines of the strong A$^1\Pi$ $\leftarrow$ X$^1\Sigma^+$ transition around 227~nm are rotationally closed and thereby suitable for the main cooling cycle. The same holds for the narrow, spin-forbidden a$^3\Pi$ $\leftarrow$ X$^1\Sigma^+$ transition around 367 nm which has a recoil limit in the micro Kelvin range. We here report on the spectroscopic characterization of the lowest rotational levels in the a$^3\Pi$ state of AlF for $v=0-8$ using a jet-cooled, pulsed molecular beam. An accidental AC Stark shift is observed on the a$^3\Pi_0, v=4$ $\leftarrow$ X$^1\Sigma^+, v=4$ band. By using time-delayed ionization for state-selective detection of the molecules in the metastable a$^3\Pi$ state at different points along the molecular beam, the radiative lifetime of the a$^3\Pi_1, v=0, J=1$ level is experimentally determined as $\tau=1.89 \pm 0.15$~ms. A laser/radio-frequency multiple resonance ionization scheme is employed to determine the hyperfine splittings in the a$^3\Pi_1, v=5$ level. The experimentally derived hyperfine parameters are compared to the outcome of quantum chemistry calculations. A spectral line with a width of 1.27 kHz is recorded between hyperfine levels in the a$^3\Pi, v=0$ state. These measurements benchmark the electronic potential of the a$^3\Pi$ state and yield accurate values for the photon scattering rate and for the elements of the Franck-Condon matrix of the a$^3\Pi$ $-$ X$^1\Sigma^+$ system. Comment: 16 pages, 9 figures |
| Databáze: | OpenAIRE |
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