Coloration by surface nanostructuring has attracted a great deal of attention by the virtue of making use of environment-friendly recyclable materials and generating nonbleaching colors. Recently, it was found possible to delegate the task of color printing to laser postprocessing that modifies carefully designed and fabricated nanostructures. Here we take the next crucial step in the development of structural color printing by dispensing with preformed nanostructures and using instead near-percolation metal films atop dielectric-metal sandwiches, that is, near-percolation plasmonic reflector arrays. Scanning rapidly (∼20 μm/s) across 4 nm-thin island-like gold films supported by 30 nm-thin silica layers atop 100 nm-thick gold layers with a strongly focused Ti-sapphire laser beam, while adjusting the average laser power from 1 to 10 mW, we produce bright colors varying from green to red by laser-heating-induced merging and reshaping of gold islands. Selection of strongly heated islands and their reshaping, both originating from excitation of plasmonic resonances, are strongly influenced by the polarization direction of laser illumination, so that the colors produced are well pronounced only when viewed with the same polarization. Conversely, the laser color writing with circular polarizations results in bright polarization-independent color images. The fabrication procedure for near-percolation reflector arrays is exceedingly simple and scalable to mass production, while the laser-induced modification occurs inherently with the subwavelength resolution. This combination of features makes the approach developed for laser color writing readily amenable for practical implementation and use in diverse applications ranging from nanoscale patterning for security marking to large-scale color printing for decoration.

中文翻译：

---

在近渗等离子体激元反射器阵列上激光写入鲜艳的色彩

表面纳米结构的着色由于利用了环保的可回收材料并产生了不褪色的颜色而备受关注。最近，发现有可能将彩色打印任务委托给激光后处理，该后处理会修改精心设计和制造的纳米结构。在这里，我们通过放弃预先形成的纳米结构，并在介电金属夹层结构的顶部使用近渗金属膜（即近渗等离子体激元反射器阵列），迈出了结构彩色印刷发展中的下一个关键步骤。快速扫描（〜20μm/ s），通过强聚焦钛蓝宝石激光束扫描100 nm厚金层上方30 nm薄层二氧化硅支撑的4 nm薄岛状金膜，同时调节平均激光功率从1到10 mW，我们通过激光加热引起的金岛合并和重塑来产生从绿色到红色的鲜艳颜色。强烈加热的岛的选择和它们的重塑都源于等离子体共振的激发，它们受到激光照射的偏振方向的强烈影响，因此，仅当以相同的偏振观看时，所产生的颜色才能很好地表现出来。相反，具有圆偏振的激光彩色写入会产生与偏振无关的明亮彩色图像。近渗反射器阵列的制造过程非常简单，可大规模生产，而激光诱导的修饰固有地发生在亚波长分辨率下。