Determination of CaOH and CaOCH$_3$ vibrational branching ratios for direct laser cooling and trapping

Understand

Alkaline earth monoalkoxide free radicals (MORs) have molecular properties conducive to direct laser cooling to sub-millikelvin temperatures.

• Using dispersed laser induced fluorescence (DLIF) measurements from a pulsed supersonic molecular beam source we determine vibrational branching ratios and Franck-Condon factors for the MORs CaOH and CaOCH$_{3}$.
• With narrow linewidth continuous-wave dye laser excitation, we precisely measure fluorescence branching for both $\tilde{X}-\tilde{A}$ and $\tilde{X}-\tilde{B}$ electronic systems in each molecule.
• Weak symmetry-forbidden decays to excited bending states with non-zero vibrational angular momentum are observed.