Ink-less color marking. インクを使わない新しい着色技術


Using the two-step ablation process with femtosecond (fs) laser pulses, a homogeneous nanograting with a uniform period was formed on the stainless steel. The surface color was evaluated with a photograph taken as functions of an incident angle of white light and an observation angle. We have found that the color has more variation and brightness than that of the surface with a non-uniform periodic nanostructure produced with the single-beam fs laser pulses. The results show that the nanograting can spatially disperse well the incident light into individual wavelength owing to the diffraction with high efficiency. Calculation using the grating equation reproduced the characteristic change of the colors observed as functions of these angles.

関連発表:Structural coloration of a stainless steel surface with homogeneous nanograting formed by femtosecond laser ablation (Yoshiki Tamamura & Godai Miyaji) Optical Materials Express Vol. 9, Issue 7, pp. 2902-2909 (2019). >>>