Knowledge Bank

Laser excitation spectroscopy has been employed in the first observation of the visible $A~2\Pi -X~2\Sigma$ electronic transition of YbOH. YbOH radicals were produced in a Broida-type oven by the reaction of ytterbium metal vapor with $H2O2$ vapor. A Coherent 599 dye laser operating in broadband mode ($1cm-1$bandwidth) was used to investigate the vibrational structure of the $A~-X~$ system at low-resolution. The output of a Coherent 699-29 ring dye laser operating in single frequency mode was used with selective detection of fluorescence to record high-resolution spectra of the $000-000$ and $000-100$ bands in the range $575-595$ nm; the measurement accuracy of the line positions was $0.003cm-1$. The results are consistent with a linear structure for YbOH. The vibrational and rotational analysis of the $A~-X~$ transition will be discussed.