Scientists in Singapore have successfully rendered an uber-high quality photo with a resolution of 100,000 dots per inch.
The research team, which recently detailed its efforts in Nature Nanotechnoloy, created the pixels using nanoscale posts - with silver and gold nanodiscs on top.
According to Dr. Karthik Kumar, the distance between the structures and their diameter is responsible for determining the color of reflected light.
"These colors are preserved even when only four disks are present in individual pixels of 250 × 250 nm squares, thus enabling color printing at a resolution of ~100,000 d.p.i.," Kumar explained.
"This printing resolution brings us to the limit of visible-light imaging, where the individual color pixels are just barely resolvable using diffraction-limited optics. Beyond obvious applications in high-resolution print image production, this method can also be used in optical data storage and color filters in lighting and imaging technologies."
To demonstrate a proof of concept, the researchers printed a 50 x 50 micrometer image of Swedish model Lena Söderberg from a 1972 issue of Playboy magazine which hit a very impressive 100,000 DPI resolution.
"Instead of using different dyes for different colours, we encoded color information into the size and position of tiny metal disks. These disks then interacted with light through the phenomenon of plasmon resonances," said Dr. Joel Yang.
"[We then] built a database of color that corresponded to a specific nanostructure pattern, size and spacing. These nanostructures were then positioned accordingly. Similar to a child's 'coloring-by-numbers' image, the sizes and positions of these nanostructures defined the 'numbers'. But instead of sequentially colouring each area with a different ink, an ultrathin and uniform metal film was deposited across the entire image causing the 'encoded' colours to appear all at once, almost like magic!"
Kumar and Yang have applied for a patent to cover their research, which they hope to commercialize ASAP. Potential uses may ultimately include nanoscale watermarks, cryptography, and packing huge amounts of data on a physical medium like a DVD or Blu-ray for archival purposes.