Nature Mater. 11, 432–435 (2012)

Credit: © 2012 NPG

Over the past decade, researchers have put a significant amount of effort into the realization of optical imaging at resolutions beyond the diffraction limit. However, current techniques either require the lens to be very close to the object, suit only certain samples or suffer from significant losses, thus impeding their use in practical devices. Nikolay Zheludev and co-workers from the University of Southampton and the University of Bristol in the UK have now developed a super-resolution imaging technique that focuses laser light to a subwavelength spot by tailoring the interference between a large number of beams diffracted from a nanostructured mask. The researchers report a super-resolution of λ/6, although in principle the device has no physical resolution limit. This technique suits imaging at any wavelength, but requires the object to be no more than tens of micrometres away from the mask.