Plasmonic activity of large-area gold nanodot arrays on arbitrary substrates.

Highly efficient fabrication of well-ordered, embedded gold nanodot matrices using diffraction mask projection laser ablation is demonstrated. These gold nanodot arrays are ideally generated onto sapphire substrates but do also form onto AlO(x) thin films, enabling the application to arbitrary bulk substrates. Well-ordered gold dots become embedded into the Al(2)O(3) substrate during the process, thus improving their mechanical stability, chemical inertness, and technological compliance. Such substrates may be useful, for example, to enhance solar-cell efficiency by surface plasmons or as convenient, biocompatible focusing elements in nearfield optical tweezers.