Nonlinear Laser Spectroscopy
CRF Nonlinear Laser Spectroscopy research focuses on developing innovative laser-based optical wave-mixing strategies for the detecting and quantifying important combustion radicals, major species concentrations, and temperature. Our researchers emphasize techniques that exhibit high spatial and temporal resolution and explore the fundamental physical and chemical processes that directly affect quantitative application of these techniques. These investigations include studying fundamental spectroscopy, energy transfer, and photochemical processes. This research aspect is essential to correctly interpreting diagnostic signals, enabling reliable comparisons of experimental data, and detailed combustion models. These investigations use custom-built tunable picosecond lasers, which enable efficient nonlinear excitation, provide high temporal resolution for pump/probe studies of collisional processes, and are amenable to detailed physical models of laser-molecule interactions. Nonlinear optical techniques investigated in this program include
- time-resolved coherent anti-Stokes Raman spectroscopy,
- degenerate four-wave mixing,
- coherent 1D and 2D imaging techniques,
- two-color four-wave mixing, and
- polarization spectroscopy.