Towards Femtosecond Laser-induced Periodic Surface Structures in Developing Functional Surface Properties

Surface morphology is a key factor in controlling the wetting, mechanical, chemical and biological properties of a surface. The surface morphology is  mostly  performed  with  well-established  lithography techniques However, these techniques have a lot of drawbacks. The alternative can be lasers, especially ultrashort lasers, which offer a potentially simple and low-cost alternative. Surface modifications by lasers with a pulse duration in the femtosecond range have recently attained a lot of attention due to nonthermal ablation mechanisms [1]. Femtosecond pulses have also been exploited to induce periodic surface structures known as laser-induced periodic surface structures (LIPSS), firstly observed in 1965. These sub-micro and nanostructures are already used and have a potential to be applied in numerous fields, including holography, photonics, wettability and medicine [2]. The advanced method to generate LIPSS – HR (highly-regular) – LIPSS  has been presented in 2016 [3]. HR-LIPSS allows fabrication of extremely uniform nanostructures, with excellent long-range repeatability.

Alongside with HR-LIPSS the ultrashort laser light by tuning of parameters allows to form a broad range of nano and microstructures. The period of structures can be changed by tuning  angle of incidence for laser light or by changing a laser wavelength. The height and morphology are strongly dependent on laser fluence while direction of structures can be tuned by optics configuration.

In this study, the most recent applications of femtosecond laser surface modification including burst mode regime will be presented.