Fig. 11
From: Plasmonic- and dielectric-based structural coloring: from fundamentals to practical applications
a (i) Photograph of a silver-based coin induced by laser with large dimensions of 21-cm diameter and 2.5-cm thickness when compared to butterfly images in detail later. (ii) Close-up image of (i) illustrating detailed coloring. Butterfly shapes on the coin (iii) before and (iv) after laser irradiation. b Color palettes at (i) nonburst mode and (ii, iii) burst mode. In (i) 25 colors were produced by varying line spacing in from 1 to 13.5 µm increments of 0.5 µm. In (ii), the color palette was created by tuning machining speed from 40 to 210 mm/s in increments of 5 mm/s. In (iii), the color palette is generated by changing machining angle between machining direction and polarization of light. Column A: 2 passes at 270°; Column B: 1 pass at 270° and 1 pass at 234°; C: 1 pass at 270° and 1 pass at 191°; D: 1 pass at 270° and 1 pass at 162°; E: 1 pass at 270° and 1 pass at 126°. Rows represent spacing between lines 1–5 µm [140]