title: Communication: hybrid femtosecond/picosecond rotational coherent anti-Stokes Raman scattering thermometry using a narrowband time-asymmetric probe pulse.
abstract: A narrowband, time-asymmetric probe pulse is introduced into the hybrid femtosecond/picosecond rotational coherent anti-Stokes Raman scattering (fs/ps RCARS) technique to provide accurate and precise single-shot, high-repetition-rate gas-phase thermometric measurements. This narrowband pulse-generated by inserting a Fabry-Pérot étalon into the probe-pulse beam path-enables frequency-domain detection of pure-rotational transitions. The unique time-asymmetric nature of this pulse, in turn, allows for detection of resonant Raman-active rotational transitions free of signal contamination by nonresonant four-wave-mixing processes while still allowing detection at short probe-pulse delays, where collisional dephasing processes are negligible. We demonstrate that this approach provides excellent single-shot thermometric accuracy (<1% error) and precision (~2.5%) in gas-phase environments.
authors.affiliation: Spectral Energies, LLC, 5100 Springfield St., Suite 301, Dayton, Ohio 45431, USA. hans.stauffer.ctr@wpafb.af.mil
authors.forename: Hans U
authors.initials: HU
authors.lastname: Stauffer
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Miller
authors.forename: Sukesh
authors.initials: S
authors.lastname: Roy
authors.forename: James R
authors.initials: JR
authors.lastname: Gord
authors.forename: Terrence R
authors.initials: TR
authors.lastname: Meyer