Journal or Book Title
A method for simultaneous ro-vibrational and pure-rotational hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS) is presented for multi-species detection and improved temperature sensitivity from room temperature to flame conditions. N2∕CH4 vibrational and N2∕O2∕H2 rotational Raman coherences are excited simultaneously using fs pump pulses at 660 and 798 nm, respectively, and a common fs Stokes pulse at 798 nm. A fourth narrowband 798 nm ps pulse probes all coherence states at a time delay that minimizes nonresonant background and the effects of collisions. The transition strength is concentration dependent, while the distribution among observed transitions is related to temperature through the Boltzmann distribution. The broadband excitation pulses and multiplexed signal are demonstrated for accurate thermometry from 298 to 2400 K and concentration measurements of four key combustion species.
This paper was published in Optics Letters and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: https://www.osapublishing.org/ol/abstract.cfm?uri=ol-39-23-6608. 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
Dedic, Chloe Elizabeth; Miller, Joseph D.; and Meyer, Terrence R., "Dual-pump vibrational/rotational femtosecond/ picosecond coherent anti-Stokes Raman scattering temperature and species measurements" (2014). Mechanical Engineering Publications. 172.