Romphosri S.Oo P.S.Karanyasopon P.Traiphhol R.Waritanant T.Mahidol University2023-06-202023-06-202022-09-01Applied Physics B: Lasers and Optics Vol.128 No.9 (2022)09462171https://repository.li.mahidol.ac.th/handle/20.500.14594/87449Two-photon polymerization (TPP) technologies commonly rely on femtosecond lasers such as Ti:sapphire which limits their accessibility due to high costs and complexities. Recently, multiple reports showed TPP under near-infrared irradiation which enables the use of alternative light sources such as Neodymium-doped lasers known to be affordable and efficient for a nanosecond and picosecond pulsed generation. 4,4′-Bis(dimethyl-amino) benzophenone or Michler’s ketone (MK), one of the photoinitiators commonly used for photopolymerization under UV irradiation, also shows an absorption band in the visible region which allows for two-photon polymerization at the fundamental wavelength of Neodymium-doped lasers at 1064 nm. In this report, we investigated the two-photon absorption (TPA) of MK in contrast with Irgacure-784 and Indane-1,3-dione, reported to also be promising photoinitiators for the same TPP process. Among them, MK showed a large TPA cross-section measured via the nonlinear transmission method and Z-scan technique with Q-switched Nd:YAG nanosecond pulse laser at 1064 nm, demonstrating MK as a promising photoinitiator for the low-cost two-photon polymerization.Physics and AstronomyArticleSCOPUS10.1007/s00340-022-07888-72-s2.0-85135867074