High-resolution degenerate four-wave mixing spectra of the R1(9) A2Σ+ → X2Π(0,0) transition of OH have been measured in a hydrogen/oxygen flame at atmospheric pressure where the Doppler and homogeneous linewidths are of comparable magnitude. The observed sub-Lorentzian Doppler-free line profile is fit well by existing perturbative models by using homogeneous broadening consistent with two-photon absorption measurements. Power broadening of the spectral profile with increasing pump-beam intensity was observed and is compared with predictions from a nonperturbative two-level model.
© 1992 Optical Society of America
Original Manuscript: August 30, 1991
Published: January 1, 1992
Michael S. Brown, Thomas Dreier, and Larry A. Rahn, "High-resolution degenerate four-wave mixing spectral profiles of OH," Opt. Lett. 17, 76-78 (1992)