Study Of Fabrication Color Metal With Multi-polarization Femtosecond Laser

The technology of the optical properties of metal surfaces changed by femtosecond laser gradually formed a new research direction. There two aspects in deciding color display of metal surfaces, on the one hand, it depends on the characteristics of the microstructure formed on the metal surfaces, and on the other hand, it relies on the viewing angle. As a result, it is necessary to explore the preparation techniques of micro/nano structures on the surfaces and study the effect of the viewing angle on color display. Linearly polarized and circularly polarized femtosecond laser scanning processes are used to prepare colored metal on the iron and316L stainless steel in this paper. We study the preparation of micro structures on metal surfaces by different polarized femtosecond laser, then explore the relationship between microstructures and the formation of colored metal, and investigate the effect of the viewing angle on the display of colored metal using different directions of microstructures. These prepare a foundation for controlling the femtosecond laser effectively to prepare colored metal. The main contents and conclusions are as follows:Describing the development and the research status of femtosecond laser preparation of colored metal. Building a complete system of femtosecond laser micro/nano fabrication corresponding experiments in the text.The technology of the optical properties of metal surfaces changed by femtosecond laser forming mechanisms and phenomenao Firstly, preparing surface microstructure on the surface of iron and stainless steel using linearly polarized of the0°,45°,90°,135°and circularly polarized femtosecond laser. Analyzing the characteristics of the formed microstructure by the Scanning Electron Microscope (SEM). Directions of periodic surface structures generated by linearly polarized femtosecond laser perpendicular to the polarization, and the periodic of the microstructure is less than the wavelength of the incident light. While circularly polarized femtosecond laser fabricated periodic micro/nano structures and nanoparticles. Explaining the reasons for the formation of the two microstructures through theoretical analysis.Secondly simulating the optical properties of femtosecond laser-induced microstructures using FDTD Solutions, study the impact of characteristic parameters on the absorption and transmittance of metal surfaces, and then further investigate the effects of different micro/nano structures on the formation of metal surface color. Finally, studying the reason of the formation on metal surfaces systematically. First, observing the area on surface of the iron and stainless steel scanned by linearly polarized laser, observing color pattern in single regional and multi-regional, changing the angle of incidence of white light, the direction and observation angle of periodic micro/nano structures of metal surfaces to achieve multi-regional and multi-color display and theoretically explained the observed phenomena. Second, studying the iron and steel in single region prepared by circularly polarized laser in the same way. Comparing with the region prepared by linearly polarized laser, the color patterns are more eye-catching, and most are transitional color and composite color which have the same spectral range.Studies have shown that changing the linear polarization direction can achieve processing in multi-zone displaying multi-pattern. Under certain conditions, different information (color) can be read. The two polarization states have the same range of the color spectrum. Colored areas prepared by circular polarization have the same research value as linear polarization. This work will lay a good foundation for colored metal prepared by femtosecond laser.