This website uses cookies primarily for visitor analytics. Certain pages will ask you to fill in contact details to receive additional information. On these pages you have the option of having the site log your details for future visits. Indicating you want the site to remember your details will place a cookie on your device. To view our full cookie policy, please click here. You can also view it at any time by going to our Contact Us page.

World's thinnest lens to revolutionise cameras

11 March 2016

Scientists have created the thinnest lens, one two-thousandth the thickness of a human hair, opening the door to flexible computer displays and miniature cameras.

Dr Lu (left) with student Jiong Yang, with the lens on screen. (Credit: Stuart Hay, ANU)

Lead researcher Dr Yuerui (Larry) Lu from ANU Research School of Engineering said the discovery hinged on the remarkable potential of the molybdenum disulphide crystal.

"This type of material is the perfect candidate for future flexible displays," said Dr Lu, leader of Nano-Electro-Mechanical System (NEMS) Laboratory in the ANU Research School of Engineering.

"We will also be able to use arrays of micro lenses to mimic the compound eyes of insects."

The 6.3-nanometre lens outshines previous ultra-thin flat lenses, made from 50-nanometre thick gold nano-bar arrays, known as a metamaterial.

"Molybdenum disulphide is an amazing crystal," said Dr Lu

"It survives at high temperatures, is a lubricant, a good semiconductor and can emit photons too.

"The capability of manipulating the flow of light in atomic scale opens an exciting 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.

Dr Lu's team created their lens from a crystal 6.3-nanometres thick - 9 atomic layers - which they had peeled off a larger piece of molybdenum disulphide with sticky tape.

They then created a 10-micron radius lens, using a focussed ion beam to shave off the layers atom by atom, until they had the dome shape of the lens.

The team discovered that single layers of molybdenum disulphide, 0.7-nanometres thick, had remarkable optical properties, appearing to a light beam to be 50 times thicker, at 38-nanometres. This property, known as optical path length, determines the phase of the light and governs interference and diffraction of light as it propagates.

"At the beginning we couldn't imagine why molybdenum disulphide had such surprising properties," said Dr Lu.

Collaborator Assistant Professor Zongfu Yu at the University of Wisconsin, Madison, developed a simulation and showed that light was bouncing back and forth many times inside the high refractive index crystal layers before passing through.

Molybdenum disulphide crystal's refractive index, the property that quantifies the strength of a material's effect on light, has a high value of 5.5. For comparison, diamond, whose high refractive index causes its sparkle, is only 2.4, and water's refractive index is 1.3.

This study is published in the Nature serial journal Light: Science and Applications.


Print this page | E-mail this page