Single crystalline optical antennas

The authors demonstrate the use of very large (>;100 μm²) but thin (<;80 nm) chemically grown single-crystalline gold flakes, which, after immobilization, serve as an ideal basis for focused-ion beam milling and other top-down nanofabrication techniques on any desired substrate. Using this methodology we obtain high-definition ultrasmooth gold nanostructures with superior optical properties and reproducible nano-sized features over micrometer length scales. The approach overcomes the current fabrication bottleneck and opens the road for the realization of extended plasmonic circuitry.