Journal or Book Title
Rotational-level-dependent dephasing rates and nonresonant background can lead to significant uncertainties in coherent anti-Stokes Raman scattering (CARS) thermometry under high-pressure, lowtemperature conditions if the gas composition is unknown. Hybrid femtosecond/picosecond rotational CARS is employed to minimize or eliminate the influence of collisions and nonresonant background for accurate, frequency-domain thermometry at elevated pressure. The ability to ignore these interferences and achieve thermometric errors of <5% is demonstrated for N2 and O2 at pressures up to 15 atm. Beyond 15 atm, the effects of collisions cannot be ignored but can be minimized using a short probe delay (~6.5 ps) after Raman excitation, thereby improving thermometric accuracy with a time- and frequency-resolved theoretical model.
This paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on tahe OSA website: https://www.osapublishing.org/oe/abstract.cfm?uri=oe-20-5-5003. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.
Optical Society of America
Miller, Joseph D.; Dedic, Chloe Elizabeth; Roy, Sukesh; Gord, James R.; and Meyer, Terrence R., "Interference-free gas-phase thermometry at elevated pressure using hybrid femtosecond/picosecond rotational coherent anti- Stokes Raman scattering" (2012). Mechanical Engineering Publications. 183.