Numerical approach for optically limited pulse transmission in polymer-phthalocyanine composite systems

The use of guest-host systems, where phthalocyanines assume the role of guest inclusions in an otherwise homogeneous host polymer film, is a feasible method toward applying the phthalocyanine moiety in a solid-state passive optical limiter. In this contribution, a preparation method for the fabrication of such composite films followed by optical limiting experiments in the nanosecond regime at 532 nm is presented for Zn phthalocyanines. A simple approximate nonlinear absorption coefficient based on molecular orbital analysis is developed allowing one use of two "yardstick" parameters to quantify the nonlinear optical response. Additionally this nonlinear absorption coefficient is folded with the distribution of energy in the exciting pulse to model more closely the experiment and it is shown that by omission of this spatial resolution one may underestimate the numerical magnitudes of the nonlinear optical parameters.