Pressure-induced lineshifts in the 2<-0 band of CO self-perturbed and perturbed by He, Kr, O-2, and N-2

The pressure-induced shifting coefficients for self-, He-, Kr-, O-2-, and N-2-broadened lines of CO in the first overtone band have been measured using a tunable difference-frequency laser spectrometer. The lineshift was directly obtained from the simultaneous record of the pressure-broadened line and the same line of pure CO at low pressure. Comparisons are made with results of theoretical calculations based on a semiclassical model and different interaction potentials. It is shown that the Lineshifts mainly originate from vibrational dephasing effects. Although the finer details of the J dependence of the shifts are not: accurately reproduced, their general trends are well predicted through the calculations. (C) 1996 Academic Press Inc.