## 1 Introduction  
Laser-induced structuring has become a versatile technique to modify the surface properties of various materials. Whether used for art features and decorative purposes or for scientific applications to produce multifunctional surfaces, laser structuring has become highly captivating in technological and scientific communities [1; 2; 3; 4]. The unique ability of high-power short laser pulses to modify almost all kinds of materials on the nanoscale poses great potential for various novel applications in optics, optoelectronics, microfluidics, color marking, and mechanics [5; 6]. Femtosecond laser processing allows precise control over local nanosized structures on material surfaces to make them highly effective and multifunctional, particularly, in the coloring and modification of surfaces wettability [7; 8; 9; 10]. Laser-induced coloring is environment-friendly as it eliminates the usage of any pigments or chemicals, while being quite flexible in achieving the desired results by optimizing laser irradiation parameters [11]. During the interactions of intense laser irradiation with material surfaces, different features may be induced. Highly-localized laser energy deposition can be achieved by a variety of means, the most efficient of which are using a tightly focused beam with its peak power just above the melting threshold [12], or by utilizing the optical near field effects [13], as well as the interference of several Gaussian laser beams [14]. The former method can be applied for generating jet-like structures and their arrays, including the fabrication of spiral surface structures [15], whereas the latter was recently utilized in the generation of periodic patterns on metals with UV laser pulses [16]. Formation of periodic structures occurs when the power of the laser beam is close to the damage threshold of the material's surface. During such surfaces restructuring, the developed structures are typically of the size of the laser wavelength and shorter, and can possess a high spatial resolution [17; 18]. Laser-induced nanoripples or Laser Induced Periodic Surface Structures (LIPSS) have revealed promising optical, magnetic, hydrophobic, and morphological properties and have found a number of relevant applications [19]. The excitation of Surface Plasmon-Polariton (SPP) and its interference with the incident electromagnetic field has been well-received in the femtosecond laser community as a possible mechanism responsible for the generation of LIPSS [20]. Besides the spontaneous generation of LIPSS structures on different materials [21], the laser beam interference method has been used to create deterministic patterns with predesigned period and controlled surface profile [22]. In this case the interference can lead to laser intensity redistribution across the irradiated surface and result in periodic modulations of the laser heating. The resulting periodic patterns, therefore, can exhibit a variety of colors that can be iridescent or angle dependent [23; 24]. Furthermore, coloring of metal surfaces can also depend on the formation of irregularly distributed nanostructures. In this case, the developed structure change of the material surface absorption [25] which is the main reason behind the coloration, while the generated colors do not change with a viewing angle [26; 27]. Another application of laser-induced surface modification is the control of the wettability response of metallic surfaces, which is currently a topic of growing interest in the laser processing of materials [8; 28]. Surfaces can be modified with intense lasers to be water attracting (hydrophilic) or water repelling (hydrophobic). Such modified surfaces have many applications such as self-cleaning [29], corrosion prevention [30], drag reduction [31], anti-bacteria [32], anti-fogging [33], and in heat transfer applications [34]. Table 1 shows some of the potential applications of laser induced surface structures.