Scientists have created the world's thinnest lens, one two-thousandth the thickness of a human hair, opening the door to flexible computer displays and a revolution in miniature cameras. The 6.3-nanometre lens outshines previous ultra-thin flat lenses, made from 50-nanometre thick gold nano-bar arrays, known as a metamaterial.
The new development utilises the remarkabable characteristics of molybdenum disulphide crystals, which is resistant to high temperatures, is a lubricant, a good semiconductor and can emit photons too.
According to lead researcher Dr Yuerui Lu from the Australian National University, the capability of manipulating the flow of light in atomic scale opens an avenue towards unprecedented miniaturisation of optical components and the integration of advanced optical functionalities.
Molybdenum disulphide is in a class of materials known as chalcogenide glasses that have flexible electronic characteristics that have made them popular for high-technology components.
The team discovered that single layers of molybdenum disulphide, 0.7 nanometres thick, have remarkable optical properties, appearing to a light beam to be 50 times thicker. This property, known as optical path length, determines the phase of the light and governs interference and diffraction of light as it propagates.
As the researchers found, the reason for this property is that light is bouncing back and forth many times inside the high refractive index crystal layers before passing through.
This study is published in the Nature serial journal Light: Science and Applications.