POB Seminar - Single-photon-assisted two-photon polymerization (Christmas Special)

The EPFL Photonics Chapter (EPC) is very pleased to announce and cordially invite you to our monthly ‘Pizza-Optics-Beer’ (POB) seminar on December 12th, at 18:15 in room CO 016.


This month we will have the pleasure to host Buse Unlu - doctoral assistant in Laboratory of Applied Photonics Devices with the presentation entitled:

        "Single-photon-assisted two-photon polymerization"


In this special edition, we are offering freshly cooked mulled wine following the pizza.

For organizational purposes (if you want to eat pizza!), please confirm your participation using this Doodle.
Don’t hesitate to extend the invitation to any postdoc and colleague!

Hope to see you there,
The team of the EPFL Photonics Chapter



Abstract:
Photopolymerization is a light-based additive manufacturing technique that facilitates the fabrication of complex 3D structures quickly and cost-effectively. One-photon polymerization allows printing with high speed despite its limited resolution. In contrast, two-photon polymerization (2PP) offers high precision and resolution but requires longer printing times. We propose a method combining 2PP and one-photon absorption (1PA) to take advantage of the dual capabilities, allowing for faster printing while preserving high resolution and enhancing depth sectioning. In this study, we employ blue light to pre-excite a photocurable resin for rapidly reaching the polymerization threshold by 1PA and a precisely focused femtosecond (fs) beam to provide the missing energy for surpassing the threshold and solidifying the resin through two-photon absorption. First, we investigate the impact of the pre-sensitization by a blue light illumination on 2PP, demonstrating the effect on voxel growth dynamics. After that, we introduce a custom 3D printer utilizing blue light sensitization in a light-sheet configuration on 2PP. We report printed 3D objects for which the average fs laser power was reduced by 28.6 % and the exposure time was reduced by a factor of two compared with polymerization performed only with the fs laser beam. Additionally, a 63 % improvement in axial voxel size was attained through blue light-sheet pre-sensitization.


You don't know POBs?
POBs (Pizza-Optics-Beer) are monthly seminars organized by the student association EPFL Photonics Chapter.
A PhD or a postdoc gives a 20-minutes presentation about his/her research in photonics. Discussions continue informally around pizza and beers!
The event is free and open to anyone.

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We thank the Doctoral Program in Photonics (EPDO), the Society of Photo-Optical Instrumentation Engineers (SPIE.), Optica and SwissPhotonics for their support.