Laser-based sensor for measuring combustion parameters

A system having a plurality of multiplexed laser sensors operating at a plurality of selective wavelengths for non-intrusively and simultaneously measuring combustion parameters including carbon dioxide (CO2) along a single optical path in a high temperature gas flow containing water vapor (H2O), wherein the improvement comprising:

• one of said laser sensors operating at a wavelength substantially near 2 μm spectrally interrogates a selective R(50) spectroscopic transition of the ν1+2ν2+ν3 CO2 absorption band in near-infrared for accurate measurements of CO2, wherein
• said R(50) spectroscopic transition is substantially isolated from interfering absorption by high temperature species present in said high temperature gas flow.