Isotopologue-selective laser cooling of molecules

We will report on isotopologue-selective optical cycling, imaging and laser cooling of 136BaF molecules. The manipulation of 136BaF is achieved without being influenced by, or affecting, the order of magnitude more abundant 138BaF isotopologue in the same molecular beam. Our approach can yield intense beams and high-fidelity detection of 136BaF and other laser-coolable molecular isotopologues of choice. Such beams are a first step towards isotopologue-selective molecular trapping and will be useful for applications in cold chemistry and precision tests of fundamental symmetries.