Analysis of the nonlinear transmission properties of some naphthalocyanines

In our search for the definition of new molecular compounds combining low linear absorption with high nonlinear optical absorption in the same wavelength range, we have prepared a series of vanadyl, chloroindium and lead naplithalocyaninato complexes with a relatively low linear optical absorption within the visible range when compared to phthalocyanines, but with similar chemical stability. The transmission properties of these complexes for nanosecond pulses at 532 nm have been evaluated and confronted in both linear and nonlinear regimes. Halogenated naphthalocyanines displayed the best optical-limiting performances. It was also found that an increase in concentration generally results in a reduction of the limiting efficiency of the systems, due to the phenomena of intermolecular aggregation and consequent excited-state quenching. Copyright (c) 2006 Society of Porphyrins & Phthalocyanines.