Branching Ratios, Radiative Lifetimes, and Transition Dipole Moments for YbOH

Medium resolution (Delta(nu) over tilde similar to 3 GHz) laser-induced fluorescence (LIF) excitation spectra of a rotationally cold sample of YbOH in the 17300-17950 cm(-1) range have been recorded using two-dimensional (excitation and dispersed fluorescence) spectroscopy. High resolution (Delta lambda similar to 0.65 nm) dispersed laser-induced fluorescence (DLIF) spectra and radiative decay curves of numerous bands detected in the medium resolution LIF excitation spectra were recorded. The vibronic energy levels of the (X) over tilde (2) Sigma(+) state were predicted using a discrete variable representation approach and compared with observations. The radiative decay curves were analyzed to produce fluorescence lifetimes. DLIF spectra resulting from high resolution (Delta(nu) over tilde < 10 MHz) LIF excitation of individual low-rotational lines in the <(A)over tilde>(2)Pi(1/2) (0,0,0)-(X) over tilde (2)Sigma(+)(0,0,0), (A) over tilde (2) Pi(1/2) (1,0,0-(X) over tilde (2)Sigma(+)(0,0,0), and [17.73]Omega = 0.5(0,0,0)-(X) over tilde (2)Sigma(+)(0,0,0) bands were also recorded. The DLIF spectra were analyzed to determine branching ratios which were combined with radiative lifetimes to obtain transition dipole moments. The implications for laser cooling and trapping of YbOH are discussed.