Lamb dip in CO lasers

Measurements are reported of the Lamb dip on 16 vibrational-rotational lines of low-pressure CO lasers. The experimental curves are fitted to a theory that takes into account velocity-changing collisions of the lasing molecules. The inhomogeneous and homogeneous linewidths, velocity-changing collision rate, and saturation intensities are determined for a gas mixture typical in sealed-off CO lasers.