Chadwick, Helen JaneHundt, Phil MortenReijzen, VanEduard, MaartenYoder, Bruce L.Beck, Rainer D.2014-02-072014-02-072014-02-07201410.1063/1.4861054https://infoscience.epfl.ch/handle/20.500.14299/100473WOS:000330614400039Highly efficient preparation of molecules in a specific rovibrationally excited state for gas/surface reactivity measurements is achieved in a molecular beam using tunable infrared (IR) radiation from a single mode continuous wave optical parametric oscillator (cw-OPO). We demonstrate that with appropriate focusing of the IR radiation, molecules in the molecular beam crossing the fixed frequency IR field experience a Doppler tuning that can be adjusted to achieve complete population inversion of a two-level system by rapid adiabatic passage (RAP). A room temperature pyroelectric detector is used to monitor the excited fraction in the molecular beam and the population inversion is detected and quantified using IR bleaching by a second IR-OPO. The second OPO is also used for complete population transfer to an overtone or combination vibration via double resonance excitation using two spatially separated RAP processes.Molecular beamsrapid adiabatic passagetext::journal::journal article::research article