Enhanced optical limiting behaviour of indium phthalocyanine derivatives when in solution or embedded in poly(acrylic acid) or poly(methyl methacrylate) polymers

摘要

The optical limiting performance of indium phthalocyanine-based polymer thin-films with large nonlinear absorption coefficients (beta(eff)) and low limiting threshold intensity (I-lim) are described. The absorption cross-sections and the population dynamics of the excited states are also reported. The excited state absorption cross-sections (sigma(exc)) are shown to depend on the transition moment between the T-1 and T-2 states. beta(eff) values have been shown to be related to the population density of the molecules in the T-1 state. The improved optical limiting performance recorded for the investigated phthalocyanine complexes in the presence of polymer matrices has been attributed to the aggregation effects of the complexes in the polymer thin-films. The optical properties of the indium phthalocyanine moieties were found to possess robust sensitivity to a change of the polymer materials. (C) 2015 Elsevier B.V. All rights reserved.