Strong Optical Limiting of Soluble Axially Substituted Gallium and Indium Phthalocyanines

Abstract

Optical limiting in In‐ and Ga‐phthalocyanines exhibits a range of saturation densities and absorption cross‐section ratios. Substitution of the p ‐trifluoromethylphenyl group at the central metal in t Bu 4 PcGaCl and t Bu 4 PcInCl reduces the saturation energy density by a factor of >3. Tailorable optical limiting properties are shown in the Figure, which plots the nonlinear absorption coefficient as a function of intensity for the five compounds studied.