New initiator for two-photon absorption induced polymerization with a microlaser at 1.06 μm
Résumé
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 100×10−50 cm4 s photon−1 at the photoinitiation wavelength (1.06 μm). The efficiency of this new initiator is evaluated by the determination of the threshold of absorbed energy density for polymerization.