The new hologram set-up uses a metasurface made from thousands of V-shaped nanoantennas hammered into a gold foil. When a laser light shines through the bottom, it projects a hologram just 10 microns above the metasurface. Incredibly, the researchers who built the technology were able to display "PURDUE" in a space narrower than a human hair. The ability to make shapes as intricate as letters means that this technology could also be used to form pixels for future displays, even 3D ones. Changing shapes is as easy as rearranging the nanoantennas on the metasurface.
So if you think Apple's Retina display is impressive, well, you ain't seen nothing 'til you've seen nano-sized holograms. More here.