One-dimensional time-resolved single-shot femtosecond coherent anti-Stokes Raman scattering thermometry in reacting thermal gradients

Time-resolved thermometry is vital for quantitative characterization of reacting turbulent flows but remains largely limited to point measurements, making higher-dimensional approaches attractive for capturing spatiotemporal thermal gradients. In this work, a one-dimensional chirped-probe pulse coherent anti-Stokes Raman scattering (CARS) instrument has been developed for gas-phase thermometry. Calibration and characterization of the instrument are detailed, and its capability is demonstrated through measurements in a laboratory flame. The ro-vibrational transitions of N 2 are targeted in a uniform temperature flow field to calibrate the instrument and extract necessary laser parameters. The best-fit modeled laser parameters are examined in detail. Variations in laser parameters along the measurement line are captured and show dependence on non-uniform beam propagation and probe volume number density. After calibration, the instrument is successfully applied to a thermal gradient generated with a cooled-wall located perpendicular to the flow of the burner combustion products.