Laser direct writing employing multi-photon 3D polymerisation is a technique famous for fusion of high-throughput and fine features down to hundreds of nm. It is already established as a scientific prototyping field and entering industry as an additive manufacturing tool used in various fields such as micro-optics, nanophotonics, biomedicine, metamaterials, programmable materials, etc. In seminar the principles of the method will be introduced, and current state-of-the-art achievements will be shown.

More details will be given on our latest research work revealing a possibility to use any color of spectrum from 500-nm-to-1200-nm with controlled pulse widths of 100-femtoseconds to realize multi-photon polymerization. It demonstrates a delicate interplay of photo-physical mechanisms more than just two-photon absorption inducing localized photo-polymerization. An evolution of the polymerised volume during direct laser writing (DLW) via different energy delivery mechanisms will be discussed: one-/two-/three-photon absorption, avalanche ionization, and thermal diffusion leading to controlled photo-polymerization. An energy deposition by X-photon absorption allows photostructuring of diverse materials without using photoinitiators. The findings are valuable for further developing of two-photon polymerization / multi-photon lithography (2PP/MPL) technology to reduce the footprint size and increase its efficiency. Understanding mechanisms and appearance of λ-tunable commercial lasers are benefiting broad applications in advanced optical additive manufacturing.

Finally controlled refractive index, high transparency and resilient as well as active micro-optical components will be showcased as their production route is enabled x-photon lithography in combination with calcination and atomic layer deposition. The achievements have immediate applications in sensing under harsh conditions, open space, and unmanned aerial vehicles (UAV).

1. Edvinas Skliutas et al., X-photon laser direct write 3D nanolithography, Virt. Phys. Prototyp. 18(1), e2228324 (2023); 10.1080/17452759.2023.2228324

2. D. Gonzalez-Hernandez et al., Single-step 3D printing of micro-optics with adjustable refractive index by ultrafast laser nanolithography, Adv. Opt. Mater. 11(14) (2023); https://doi.org/10.1002/adom.202300258

3. G. Balčas et al., Fabrication of Glass-Ceramic 3D Micro-Optics by Combining Laser Lithography and Calcination. Adv. Funct. Mater. 33(39) 2215230 (2023); https://doi.org/10.1002/adfm.202215230