By using this “self-aligned process,” Bashir says, each lens has its own perfectly aligned waveguide. Lee says his team has shown that it is “possible to micro-fabricate these structures without alignment with a machine.” This lens-making method lends itself well to mass production, he adds, because it uses only common materials and fabrication equipment. Additionally, Lee says, the process is inexpensive because the waveguides and lenses do not need to be bonded together in further, tedious steps.
Although Lee’s work is just the first demonstration of this three-dimensional lens-making technique, Bashir says it is detailed and robust: “All the key ingredients are there, and currently the process is amenable to manufacturing.”
Bashir suspects that the ideal application for the dome-shaped array is to attach it to a charge-coupled device (CCD) – a chip commonly found in digital cameras that converts light into electrical signals. The diameter of the dome matches well the millimeter length of the chip. This combining of technologies would enable cameras to take wider-angle images. This application, he says, could be just two to five years away.
Although these arrays of lenses can extend a camera’s field of view, they don’t offer a high resolution yet, says Russell Chipman, professor of optical sciences at the University of Arizona. “The number of pixels is equal to the number of lenses,” he says. Yet this resolution may still be “good enough to be applicable in some instances,” such as endoscopies. And, Chipman adds, it should not be too difficult to provide more resolution by adjusting the design of the lenses.
Overall, Chipman believes the technology is promising – the optics industry is always looking for better ways to capture images. And the lenses created by Lee and his team can collect more light than other types of lenses. “If something like this gets into the marketplace it could be competitive,” Chipman says.
Home page image courtesy of Science magazine.