Realization and characterization of tetra(tert-butyl) zinc phtalocyanine poly(methyl methacrylate) films for optical limiting applications.

We investigated optical limiting effects in films of tetra(tert-butyl) zinc phtalocyanine dissolved into poly(methyl methacrylate) within a 0.15% maximum weight ratio. Spectroscopic analysis was performed on the realized films in order to retrieve the corresponding linear optical absorption coefficient, whose interpolation according to a model including a set of three Lorentzian oscillators enabled the evaluation of the degrees of monomer and dimer concentrations. Thereafter, nonlinear transmission measurements were carried out at two different wavelengths, 532 and 634 nm. All the investigated films showed a nonlinear optical response, which was found to increase as the resonant condition was approached. [ABSTRACT FROM AUTHOR]