Figure 1
From: Plasmon enhanced optical tweezers with gold-coated black silicon

Experimental design.
(a) Scanning electron microscope (SEM) image, at side (45o) view of the surface, of an uncoated femtosecond-laser nanostructured silicon substrate. Inset: magnified view of a femtosecond-laser nanostructured silicon substrate after coating with 3 nm of copper and 50 nm of gold. (b) Schematic diagram of the optical trapping setup.