Directly-excited laser-induced thermal grating spectroscopy and thermometry with carbon dioxide vibrational transition
Laser-induced thermal grating spectroscopy (LITGS) has been proved for accurate thermometry and measurement of energy transfer processes in molecules. While electronic transitions are often used for excitation in previous LITGS works, here we report laser-induced thermal gratings formed by direct excitation of CO2 with an infrared (IR) laser at wavelength near 2 μm, with which high signal-to-noise