Suitable photo-resists for two-photon polymerization using femtosecond fiber lasers

•We have proposed reliable materials for two-photon polymerization using fixed-wavelength femtosecond fiber laser.•Optimized materials have simple processing with adequate optical and mechanical properties.•Fabricated structures show satisfying properties in terms of geometrical shape, surface quality and mechanical stability.•We have demonstrated fabrication of structures for applications to optical tweezers, plasmonics and fiber imaging.

We present suitable materials with good optical and mechanical properties, simple processing, efficient and optimized for two-photon polymerization (TPP) with femtosecond fiber lasers. We selected readily available acrylic monomer Bisphenol A ethoxylate diacrylate (BPA-EDA) with three different photo-initiators (PIs), isopropyl thioxanthone (ITX), 7-diethylamino-3-thenoylcoumarin (DETC), and 4,4′ bis(diethylamino) benzophenone (BDEB), since their absorption spectra match well with the laser wavelength at 780 nm. These PIs grant efficient radical generation, reactivity and high solubility in acrylic monomers. Finally, good optical and mechanical properties are demonstrated by the fabrication of different micro-structures.

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