Eye See You...

Kenneth Chau is excited about the newly published research that explains how he and his colleagues developed a negative-index material that can be sprayed onto surfaces and act as a lens.

A team of researchers, including a University of British Columbia engineer have made a breakthrough utilizing spray-on technology that could revolutionize the way optical lenses are made and used.

Kenneth Chau, an assistant professor in the School of Engineering at UBC’s Okanagan campus,worked with principal investigator Henri Lezec and colleagues Ting Xu, Amit Agrawal, and Maxim Abashin at the National Institute of Standards and Technology in Maryland on the development of a flat lens. Their work is published in the May 23 issue of the journal Nature.

Nearly all lenses – whether in an eye, a camera, or a microscope – are presently curved, which limits the aperture, or amount of light that enters.

“The idea of a flat lens goes way back to the 1960s when a Russian physicist came up with the theory,” Chau says. “The challenge is that there are no naturally occurring materials to make that type of flat lens. Through trial and error, and years of research, we have come up with a fairly simple recipe for a spray-on material that can act as that flat lens.” (1)

A NIST team has created an ultraviolet (UV) metamaterial formed of alternating nanolayers of silver (green) and titanium dioxide (blue). Credit: Lezec/NIST

For the first time, scientists working at the National Institute of Standards and Technology (NIST) have demonstrated a new type of lens that bends and focuses ultraviolet (UV) light in such an unusual way that it can create ghostly, 3D images of objects that float in free space. The easy-to-build lens could lead to improved photolithography, nanoscale manipulation and manufacturing, and even high-resolution three-dimensional imaging, as well as a number of as-yet-unimagined applications in a diverse range of fields.

"Conventional lenses only capture two dimensions of a three-dimensional object," says one of the paper's co-authors, NIST's Ting Xu. "Our flat lens is able to project three-dimensional images of three-dimensional objects that correspond one-to-one with the imaged object."

An article published in the journal Nature* explains that the new lens is formed from a flat slab of metamaterial with special characteristics that cause light to flow backward—a counterintuitive situation in which waves and energy travel in opposite directions, creating a negative refractive index. (2)

1. UBC engineer helps pioneer flat spray-on optical lens
2. The Better to See You With: Scientists Build Record-Setting Metamaterial Flat Lens