A research team from KAIST found an innovative method to produce a superlens from a layer of random nanoparticles. The team, headed by Professor Jun-Hoon Park and Professor Chunghyun Park from the Department of Physics, published its research in the April issue of Nature Photonics. Through an inexpensive layer of nanoparticles and white paint, they developed a superlens that is capable of having resolutions three times higher than those of conventional lenses.

Conventional lenses inherently carry a limit in image resolution due to the diffraction limit. Light called near-field waves contain information about the fine features of an object passing through a lens. For conventional lenses, images of objects anything below 250 nm cannot be obtained, as it loses its information when scattering of near-field waves occurs within the lens.

Preceding this study, researchers have attempted to reduce the scattering of light waves. Through the newly developed superlens, multiple scattering of light, which conventional lenses failed to control, was exploited to enhance image resolution in a cost effective manner. With a simple coat of white commercial spray paint and zinc oxide particles, the scattering of light within the nanoparticle layer was controlled using a spatial light modulator. The modulator changes the wavefront and phase of light entering the randomly distributed nanoparticles so that it can be controlled into focus. The method was capable of obtaining a focus of light smaller than the expected diffraction limit in ordinary lenses.

The superlens is expected to have applications in biomedical and nano-sciences. Higher resolution images are critical in observing cell structures and and biomolecules in biological sciences. Also, new opportunities for more accurate control of light in lithography may pave new paths for better semiconductor chip production methods in electronics.