High resolution spectroscopy and spectral simulation of C-2 using degenerate four-wave mixing

Degenerate four-wave mixing in the sub-Doppler phase conjugate geometry was used to record high resolution spectra of the d (3)Pi(g)-a (3)Pi(u) (0-0) Swan band of C-2 produced in an oxy-acetylene flame. The line positions of isolated transitions were measured to an accuracy of similar to 3X10(-3) cm (-1) and calibrated using a Fizeau interferometer system. The data obtained from these spectra was used to calculate rotational constants and lambda d oubling parameters for the (3)Pi states from which the line positions for t he whole band were calculated. Noticeable improvements between experimental and calculated line positions are seen when compared to previously publish ed values. The effect of inaccuracies in line positions on the simulation o f degenerate four-wave mixing spectra is discussed and some examples of the improvement in simulation using the newly calculated line positions are pr esented. (C) 1999 American Institute of Physics. [S0021-9606(99)03701-0].