Polarization of light from a pulsed dye laser: effects of solvent viscosity

A pulsed dye laser is polarized by insertion of a tilted glass plate in the cavity. The degree of polarization depends upon the cavity losses for light of the two polarizations, and we have measured the dependence for lasers in which the dye (Rh 6G) is dissolved in solvents of various viscosities. It is found that the polarization is less for higher viscosity solvents. A rate equation model is used to make numerical estimates of the effect, and these are compared with the experimental data.