Establishing a nearly closed cycling transition in a polyatomic molecule

We study optical cycling in the polar free radical calcium monohydroxide (CaOH) and establish an experimental path towards scattering similar to 10(4) photons. We report rovibronic branching ratio measurements with precision at the similar to 10(-4) level and observe weak symmetry-forbidden decays to bending modes with nonzero vibrational angular momentum. Calculations are in excellent agreement with these measurements and predict additional decay pathways. Additionally, we perform high-resolution spectroscopy of the (Chi) over tilde (2) Sigma+(12(0)0) and (Chi) over tilde (2) Sigma(+) (12(2)0) hybrid vibrational states of CaOH. These advances establish a path towards radiative slowing, three-dimensional magneto-optical trapping, and sub-Doppler cooling of CaOH.

Automated summary

The research focused on optical cycling in the polar free radical calcium monohydroxide (CaOH) and established an experimental path for achieving scattering of approximately 10^4 photons. Precise measurements of rovibronic branching ratios were reported along with observations of weak symmetry-forbidden decays to bending modes with non-zero vibrational angular momentum. High-resolution spectroscopy of hybrid vibrational states of CaOH was performed, laying the groundwork for future cooling technologies.