Photograph of the High Pressure Gaseous Burner Facility. The Nd:YAG laser provides 1000 mJ pulses at a 10 Hz rate to excite molecules such as N2, O2, H2O, H2, CO, CO2 and CH4 above the calibration burner mounted inside the high pressure test rig. The pulses from the laser are temporally stretched from about 10 ns to 100 ns using a custom pulse-stretcher shown in the foreground. The pulse-stretcher is required to reduce the peak power of the laser to prevent damaging the windows and also to prevent the laser probe volume from sparking due to the dielectric breakdown that occurs when an intense laser pulse is focused. The laser excitation causes the molecules to in-elastically scatter (or emit) a wavelength shifted light signal resulting from the Raman Effect. The Raman scattering signal is collected using a lens and fiber optic cable which then directs it to the custom designed Raman diagnostics instrumentation system. This signal is collected as a series of Raman spectra, and once interpreted, the spectra provides the quantitative measurement4 of the chemical species concentration and temperatures. The measurements provide a reference standard calibration database that enables other researchers to use Raman scattering as tool in high pressure environments. Ultimately, such measurements are needed to validate the complex turbulent combustion models that employ finite-rate chemistry.