Ultra-thin lens breakthrough that could revolutionise miniature cameras

An international team, led by researchers from Swinburne’s Centre for Translational Atomaterials, has developed an ultra-thin lens that could revolutionise miniature cameras and high-speed photonic chips.

The lens is made from a one molecule layer of atomaterials – the next generation of nanomaterials with a thickness about one millionth of a human hair in size.

It could be used in ultra-compact cameras, achieving high resolution images comparable to state-of-the-art imaging systems.

The research breakthrough has recently been reported as the cover story in the Nature journal Light Science & Application. It was co-led by Founding Director of Swinburne’s Centre for Translational Atomaterials, Professor Baohua Jia, Professor Qiaoliang Bao formerly at Monash University, and Professor Chengwei Qiu at National University of Singapore.

“Lenses are the key element in optical systems in our daily life, including eyeglasses, microscopes, magnifying glasses, and camera lenses,” says first author Swinburne’s Dr Han Lin.

“Conventional lenses based on light refraction need multiple lenses to be stacked to form compound lenses to minimise aberrations and achieve good imaging quality. Therefore, current high-quality camera equipment is complex and bulky. We have put tremendous effort into the development of ultrathin flat lenses.”

Unlike conventional lenses, a flat lens uses nanostructures to control light and correct image distortion. It can also produce different light patterns to achieve functionalities like display, coloration or optical tweezers – scientific instruments that use a highly focused laser beam to hold and move microscopic objects.

However, when the lens becomes very thin – just a single layer of atoms, for example – it cannot provide good image quality with high resolution and high contrast.

In this work, the researchers used a laser to nanoprint the surface of the monolayer materials to fabricate the lens. Unlike conventional lenses with a smooth curved surface, the monolayer lens is ultraflat and composed of concentric rings with a rough surface composed of nanoparticles.

This nanoprinting made the monolayer lens capable of providing high-resolution, high contrast images, that could be applied in a mobile phone camera to further reduce the device thickness.

“We have used the thinnest material in the world to fabricate a flat lens and prove that the good performance of the ultrathin lens can lead to high resolution imaging,” says Professor Jia.

“It shows enormous potential in different applications. Using this technique, the weight and size of camera lenses could be significantly reduced,” says Professor Chengwei Qiu.

Professor Qiaoliang Bao adds: “We are excited to see unique outcome from femtosecond laser nanoprinting of 2D materials. It opens up new possibilities to fabricate photonic devices using a scalable and low-cost method. This lens is readily integratable with existing devices.”