Metalens achieves near-unity numerical aperture

Researchers have designed an optical lens with the highest free-space numerical aperture to date, achieving a value of just under 1. As the numerical aperture indicates the highest possible resolution that a lens can attain, the new lens can focus light with unprecedented ability, as well as collect light from wide angles. These abilities should make the lens particularly useful for low-light applications, such as single-photon emission, which is often used in quantum optics systems.

The researchers, led by Arseniy Kuznetsov and Ramón Paniagua-Domínguez, at A*STAR (Agency for Science, Technology, and Research) and Nanyang Technological University, both in Singapore, have published a paper on the lens with near-unity numerical aperture in a recent issue of Nano Letters.