New initiator for two-photon absorption induced polymerization with a microlaser at 1.06 μm

Two-photon absorption (TPA) induced polymerization is a very promising way for three-dimensional (3D) microfabrication. However, the necessity to use onerous femtosecond Ti:sapphire lasers appears as a major drawback for this technology. We present a new symmetrical conjugated ketone with terminal amino groups that can initiate TPA photopolymerization of acrylates when irradiated with an inexpensive Nd-YAG microlaser. This compound shows broad band TPA between 800 nm and 1100 nm with a cross-section of 100 x 10(-50) cm(4) s photon(-1) at the photoinitiation wavelength (1.06 mum). The efficiency of this new initiator is evaluated by the determination of the threshold of absorbed energy density for polymerization. (C) 2003 Published by Elsevier Science B.V.