Optical signals of gas temperature, species concentration, and electric field are monitored in simple mixtures at room temperature and in the fuel-rich region of a hydrogen diffusion flame. A two-beam pure-rotational coherent anti-Stokes Raman scattering (CARS) approach was utilized for the temperature and species detection, where the combined pump/Stokes pulse doubled as the electric field induced second harmonic generation (EFISHG) pump for the electric field detection. Time-averaged EFISHG signals in environments with argon, nitrogen, oxygen, hydrogen, and air were found to match the relative hyperpolarizabilities of the molecules tabulated in literature. Measurements in a dynamic H 2 -air environment represented the ability to monitor the signal dependence of species on a single-shot basis. Time-averaged EFISHG signals in different thermal environments showed the expected ∝ T 1 2 EFISHG signal dependence when also correcting for relative H 2 ∕N 2 concentrations. Finally, measurements in a flame showed the ability to monitor the EFISHG signal dependence on the gas temperature on a single-shot basis in a plasma discharge environment.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Engineering (miscellaneous)
- Electrical and Electronic Engineering