Excited-state absorption and dynamics in a Pb-phthalocyanine copolymer

Transient absorption and degenerate four-wave mixing measurements on a thin film Pb- phthalocyanine-urethane-butanediol copolymer show that this material has a strong excited state absorption in the visible and near-IR. The excited state absorption cross section, (sigma) ex, exceeds that of the ground state, (sigma) g from 430 to 620 nm and at 1064 nm. DFWM measurements at 590 nm show both an instantaneous response ((tau) < 1 ps) and a long lived response from an excited state with a rise time of less than 1 ps, and a decay time of > 10 ns.