Abstract
A full vibrational–rotational level rate equation model has been used to investigate the applicability of laser-induced fluorescence techniques to number density measurements of hydroxide in a combustion environment. The variation of the population in both the laser-pumped rotational and vibrational levels was investigated for a range of pressures, temperatures, laser intensities, and collisional exchange rates when excitation is to the upper electronic state v′ = 1 vibrational level.