Dependence of relaxation of the bleached state of dye 3274u on the intensity of the exciting radiation

The method of picosecond spectroscopy was used in an investigation of the process of recovery of the absorption by dichloroethane solution of dye 3274u after resonant excitation by an ultrashort pulse. The relaxation time τ_r of the bleached state of the investigated solution depended on the power density of the exciting pulse: for 0.43 GW/cm² we found that τ_r = 14 ± 2 psec, whereas for 1.8 GW/cm² we obtained τ_r = 43 ± 2 psec.