Fabrication of color iron with multi-polarization femtosecond laser

In order to manufacture the colorful metals, the iron surface was scanned from four directions by linearly polarized and circularly polarized femtosecond lasers respectively. When the processed area which was scanned by the linearly polarized laser was observed from different directions, it appeared in different colors. However, when the iron surface was scanned by the circular polarized laser, the resulted pattern color observed from different angles changed unobviously. The experimental results were analyzed by scanning electron microscope (SEM).The results showed that the surface of the colorful metals which were scanned by the linearly polarized laser is full of laser-induced periodic surface structure covered with nanostructures (NC-LIPSS) and the periodic surface structure direction was always perpendicular to the laser polarization direction. Simultaneously, the SEM images showed that the iron periodic surface structure which was manufactured by circularly polarized femtosecond laser was not obvious, and a large number of nanoparticles were obtained.