Nonlinear Absorption Behavior of Indanthrone Dyes: Comparison of Optical Saturation and Photochemical Processes

Abstract

The nonlinear absorption of ruby laser radiation by indanthrone dyes resulted in significant temporal shaping of the transmitted laser pulse at incident flux densities greater than 30 MW/cm². This behavior and the observation that aggregation of the dye molecules is associated with the nonlinear response indicates that photochemical processes may be responsible for the effect. Models involving such processes were analyzed and the results compared to the experimental data.