## 1 Introduction  
The term 'laser' stands for _Light Amplification by Stimulated Emission of Radiation_. It is a commonly known name for a device that generates or amplifies electromagnetic radiation in the visible or invisible light range based on stimulated emission [1, 2]. Looking back in history, the basis of modern laser technologies is research by [PERSON] and his works on the photoelectric effect, quantum mechanics, quantum structure of light, and the possibilities of stimulating the emission of coherent, monochromatic, electromagnetic radiation [3]. One of the first industrial uses of a laser took place in the 1970s and involved using a beam to cut sheets of steel. Later, lasers were gradually used to modernize welding processes: welding, surfacing, heat treatment, surface modification, ablation, and cutting [3, 4, 5, 6, 7, 8, 9, 10]. Various types of laser processing mechanisms and their applications were described by [PERSON] et al. in their extensive review article [2]. The most important elements of laser construction are the active medium placed in an optical resonator with two parallel mirrors spaced at a given distance and a pumping system that provides the energy needed to excite the active medium and needed to create the necessary conditions for the active medium to amplify the light passing through it. These mirrors can be either spherical or flat. One of them is almost completely reflective. The reflectance of the second one must be lower than the first as it will act as the output mirror through which the radiation leaves the resonance cavity [11; 12]. The light generated in this way has a number of unique properties, including the following:  
* The form of a laser beam--it can either spread over long distances or concentrate a small, focused beam;
* A narrow emission spectrum;
* A continuous or pulsed emission;
* Coherent radiation, usually polarized;
* Low beam divergence;
* Short, high-power pulses. Lasers can be divided into many categories depending on power, method of operation, applications, etc. Lasers are also divided into categories according to the phase, state, or resource of the gain medium, such as a solid (e.g., solid Nd: YAG, Ti-Shappire, etc. ), liquid (e.g., dye laser), gas (e.g., He-Ne, CO\({}_{2}\), etc. ), and semiconductor (e.g., GaAs, InAs, etc.). The fiber laser, which is currently widely used in the manufacturing industry, is a type of solid laser as the active amplifying medium is an optical fiber doped with solid rare earth elements such as erbium, ytterbium, neodymium, dysprosium, praseodymium, thulium, and holmium to ensure light amplification. The wavelength of the emitted light is determined by the energy levels of the various gain media. Fiber lasers have a wide pulse operating range, and their average power output can be up to several kW. Fiber lasers enable efficient industrial processing such as steel welding, thick metal cutting, texturing for dyeing, and metal 3D printing, etc. [2; 3]. In addition to industrial applications, laser devices are used in many fields, e.g., in medicine, geodesy, military technology, astronomy, etc. [5; 6; 7; 8; 11; 13; 14; 15; 16; 17; 18]. Scientists from Slovenia used an Nd: YAG laser on ultrathin AISI 316 samples in order to enhance boiling heat transfer [18]. Polish scientists often use lasers to modify the surface layers of different biomaterials used in medicine and bioengineering [19]. A good description of the texturing was provided by [PERSON] et al., who also used laser surface texturing for bioengineering applications [10]. It is very rare for researchers to share a detailed description of sample preparation, but a few can be found. One of them was published by [PERSON] et al., who described the importance of polishing copper samples before the laser treatment [20]. Extensive experimental research conducted by [PERSON], [PERSON], and [PERSON] provides readers with profound knowledge of brass laser surfacing. The scientists mention polishing and etching the samples before the laser treatment [21].