Ultrashort (less than few picoseconds) laser pulses constitute a powerful tool for large scale precision manufacturing at both the micro and the nano scales.

The Ultrafast Laser Micro and Nano Processing Group (ULNMP) (Fig. 1) of the Institute of Electronic Structure and Laser (IESL-FORTH) is a, worldwide, pioneering team focusing on the development of advanced laser texturing and modeling tools for the biomimetic structuring of materials.

In this project, studies will be undertaken to better understand :

• the underlying mechanisms defining the laser-matter interactions between the picosecond-laser system and the target mould tool materials; and
• the formation of laser-induced hierarchical surface texture features (Fig 2a).

The theoretical and experimental results generated during these studies will be used to advance existing theories, models and modelling software for the accurate simulation (prediction) of surface texture patterns based on defined substrate materials and laser irradiation schemes. Building on the modelling software, optimization algorithms will be defined enabling the identification of the required irradiation scheme to achieve a target surface texture for a given material (Fig. 2b). Working in parallel, an optical configuration (set-up) will be developed enabling the necessary control of the picosecond laser parameters to satisfy the anticipated range of required irradiation schemes.

The optical configuration will utilize adaptive optics to enable dynamic control of the laser irradiation parameters (including fluence, polarization, beam profile, focusing conditions) during processing. The laser modeling and optics will be integrated into a prototype laser system for texturing of material surfaces.

Fig. 1

 

Fig. 2a

 

Fig. 2b

 

Relevant representative references

• Papadopoulos A., Skoulas E., Tsibidis G.D., and Emmanuel Stratakis E. (2018), ‘Formation of periodic surface structures on dielectrics after irradiation with laser beams of spatially variant polarisation: a comparative study’, Applied Physics A 124, 146.
• Tsibidis G.D., Mimidis A, Skoulas E., Kirner S.V, Krüger J, Bonse J and Stratakis E. (2018), ‘Modelling periodic structure formation on 100Cr6 steel after irradiation with femtosecond-pulsed laser beams’, Applied Physics A 124, 27.
• Tsibidis G.D., Skoulas E., A.Papadopoulos, and Stratakis E. (2016), ‘Convection roll-driven generation of supra-wavelength periodic surface structures on dielectrics upon irradiation with femtosecond pulsed lasers’, Physical Review B (Rapid Communications) 94, 081305.
• Tsibidis G.D., Skoulas E., and Stratakis E. (2015) “Ripple formation on Nickel irradiated with radially polarized femtosecond beams’, Optics Letters, 40 (22), 5172.
• Tsibidis G.D., Fotakis C., and Stratakis E. (2015), ‘From ripples to spikes: a hydro-dynamical physical mechanism to interpret femtosecond laser induced self-assembled structures’, Physical Review B (Rapid Communications), 92 ,041405.
• Tsibidis G.D., Barberoglou M., Loukakos P.A., Stratakis E., and Fotakis C. (2012) ‘Dynamics of ripple formation on silicon surfaces by ultrashort laser pulses in subablation conditions’, Physical Review B, 86, 115316.