Cross-Relaxation Effects in the Saturation of the 6328-Å Neon-Laser Line

We report experiments which show that saturation of the inhomogeneously broadened 6328-Å neon-laser line is strongly affected by cross relaxation which tends to redistribute the excited atoms over the Maxwellian velocity distribution and thus leads to partially homogeneous line saturation. Our results for ${\mathrm{Ne}}^{20}$ discharges agree well with theoretical calculations based on a "strong-collision" model. Results for ${\mathrm{He}}^3$:${\mathrm{Ne}}^{20}$x mixtures show deviations from this model that we attribute to the "weak" cross relaxation caused by He-Ne collisions.