Density Dependence in Thermal Rayleigh Scattering in Gases

Additional measurements of critical absorption coefficients and anti-Stokes shifts have been made in stimulated thermal Rayleigh scattering in C${\mathrm{O}}_2$ and C${\mathrm{H}}_4$. The threshold power for different absorption coefficients was determined as a function of density. The results are in qualitative agreement with the theoretical predictions of Gray and Herman.