Knowledge Bank

Quantum state-specific dynamics are reported for a number of CO$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ rotational states in an optical centrifuge. The optical centrifuge results from combining oppositely-chirped ultrafast laser pulses and spinning CO$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ molecules into extremely high rotational states with J$\approx$220.Collisionsofcentrifugedmoleculesinducedepletionofpopulationfromlow-Jstates(J=0and36)andleadtoappearanceofpopulationinhighJstates(J=36,54and76).TransientDoppler-broadenedlineprofilesforindividualCO$_{2}$ states reveal that the depletion populations have narrow velocity distributions with translational temperatures significantly colder than 300 K. Molecules that appear in the higher rotational states have broad velocity distributions, showing that both rotational and translational energy are imparted in collisions of the centrifuged molecules. These results show that substantial amounts of angular momentum persist after many collisions and that translational energy exchange continues for several thousand collisions.