## 4 Conclusions  
By investigating and comparing the effects of different laser light wavelengths on measurements of roughness, particularly on glossy surfaces, we gained valuable insights. This knowledge has the potential to drive the development of novel techniques and methodologies for accurately measuring surface roughness on glossy surfaces, tailored to specific materials and diverse application requirements. Furthermore, it contributes to a deeper understanding of this area, paving the way for enhanced surface analysis techniques. * In the zone with the greatest roughness of the cutting surface, the reflection of the laser light was the least. Conversely, in zones with a lower surface roughness at the cutting surface, the reflection of laser light was higher. * Of the three laser light wavelengths used, the laser light with a wavelength of \(\lambda=445\) nm achieved the best results for measuring the roughness parameters of the shiny surface. * When we compared the percentages of the measured values of the roughness parameters Ra and Rz of the shiny surface between those obtained by laser profilometry and those of the reference contact roughness meter SJ-400, we found that the values measured by laser profilometry were several times higher than the reference values. * When measuring the roughness of shiny surfaces using non-contact laser profilometry, reflections of laser light occur, which cause distortion or interference with the measured results, with the consequence of affecting the accuracy of the measurement. One way to partially limit this phenomenon is to use a special transparent coating on the surface of the sample, which absorbs some of the reflections. There is also the possibility of preventing glare by making the surface cloudy and therefore matt. * The non-contact method of laser profilometry is not suitable for accurate measurements of the roughness parameters of shiny surfaces. This conclusion is important from the point of view of choosing a suitable measurement method if precise values of the roughness of shiny surfaces are essential. In that case, we recommend using a contact roughness meter. An experiment that analyzes the effect of the color of laser light in a laser profilometer on the reflection of light from a surface can also have several practical benefits:  
* Experiments that involve using different colored spectral laser lights to measure surface roughness can help identify the optimal light color for a particular type of surface. * Different colors of light have different abilities to penetrate the material and reflect from the surface. In this way, it may be possible to highlight certain surface features and improve the visibility of details that might otherwise be less obvious or hidden. * Experiments with different colored spectral lights can provide important information about these surface properties and may help in evaluating and comparing the quality of different surfaces. Measuring surface roughness using non-contact methods such as laser profilometry is a technically challenging task. Achieving accurate measurements at such a fine level is at the limit of physical possibilities and requires careful calibration and proper setup of the measurement system. These experiments can provide valuable insights into the possibilities and limitations of these methods and contribute to the development of better techniques and procedures in the field of the measurement of surface roughness. Theseexperiments can help push the boundaries and bring innovations in the field of measuring surface roughness and creating reliable and accurate surface profiles. It is important to keep in mind that the results of this experiment may vary depending on the specific material type, the surface texture, and the measurement device's settings. Therefore, it is necessary to carry out enough repeated measurements and a thorough analysis of the results achieved. This research was funded by KEGA, grant number 015 TUKE-4/2022. Not applicable.