Novel Multi-Branched Two-Photon Polymerization Dyes of Ketocoumarin Derivatives

摘要

Novel Multi-branched two-photon absorbing dyes containing highly efficient UV-visible curing initiator, Ketocoumarin (3-acetyl-7-diethylaminocoumarin), were synthesized. Their linear and nonlinear optical properties were studied, and the cooperatively enhanced two-photon absorption of two- and three-branched dyes 2 and 3 were confirmed by femtosecond laser pulses. The largest two-photon absorbing cross-section of dye 3 was obtained as 1117 GM. The photobleaching experiments showed that all three dyes had very fast electron transferring speed with o-CI-hexaarylbisimidazoles (HABI). The two-photon polymerization of a mixed resin containing dye 2 as sensitizer and HABI as coinitiator was investigated, and the polymerization threshold of the resin film at 800 nm was obtained as 660 mJ/cm~2.