North American team pioneers flat spray-on optical lens
24 May 2013
Researchers from Canada and the US have made a breakthrough utilising spray-on technology that could change the way optical lenses are made and used.
Kenneth Chau (pictured) and colleagues have developed a negative-index material that can be sprayed onto surfaces and act as a lens (photo: University of British Columbia)
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.
Now, Kenneth Chau, an assistant professor in the School of Engineering at the University of British Columbia's (UBC's) Okanagan campus, along with colleagues at the US National Institute of Standards and Technology, have succeeded in developing a flat lens.
"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."
The research team has developed a substance that can be affixed to surfaces like a glass slide and turn them into flat lenses for ultraviolet light imaging of biological specimens.
"Curved lenses always have a limited aperture," he explains. "With a flat lens, suddenly you can make lenses with an arbitrary aperture size – perhaps as big as a football field."
While the spray-on, flat lens represents a significant advancement in technology, it is only an important first step, Chau adds.
"This is the closest validation we have of the original flat lens theory," he says. "The recipe, now that we've got it working, is simple and cost-effective. Our next step is to extrapolate this technique further, explore the effect to the fullest, and advance it as far as we can take it."
The research team believes the technology could change the way imaging devices like cameras and scanners are designed.