Modification of Nonlinear Optical Properties in CdSe/PBMA Film by High Intensity Light

Excitation-relaxation dynamics in CdSe nanocrystals passivated with tri-n-octylphosphine oxide and embedded in the poly(butylmethacrylate) polymer was investigated before and after their irradiation by high intensity laser pulses. The irradiation causes a significant bleaching of the sample absorption as well as the shift of the lowest energy absorption band to the short wavelength side. The film irradiation reduces the nonlinear transient absorption bleaching on the long wavelength side of the low energy absorption band, however, it has only minor influence on the transient absorption relaxation.